United States Court of Appeals 

for the Federal Circuit ______________________

BLACKBIRD TECH LLC, DBA BLACKBIRD 

TECHNOLOGIES,

Plaintiff-Appellant

v.

ELB ELECTRONICS, INC., ETI SOLID STATE 

LIGHTING INC., FEIT ELECTRIC COMPANY INC.,

Defendants-Appellees

______________________

2017-1703

______________________

Appeal from the United States District Court for the 

District of Delaware in Nos. 1:15-cv-00056-RGA, 1:15-cv00057-RGA, 1:15-cv-00058-RGA, 1:15-cv-00062-RGA, 

Judge Richard G. Andrews.

______________________

Decided: July 16, 2018

______________________

SEAN KEVIN THOMPSON, Blackbird Technologies, 

Boston, MA argued for plaintiff-appellant. Represented 

by WENDY VERLANDER; CHRISTOPHER FREEMAN, Chicago, 

IL; STAMATIOS STAMOULIS, Stamoulis & Weinblatt LLC, 

Wilmington, DE.

JOHN HINTZ, Maynard, Cooper & Gale, PC, New York, 

NY, argued for all defendants-appellees. 
2 BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC.

PHILIP A. ROVNER, Potter Anderson & Corroon, LLP, 

Wilmington, DE, for defendant-appellee ETi Solid State 

Lighting Inc. Also represented by JONATHAN A. CHOA,

ALAN R. SILVERSTEIN; DAVID PETER HOCHBERG, Walter 

Haverfield LLP, Cleveland, OH.

______________________

Before PROST, Chief Judge, MOORE and REYNA, Circuit 

Judges.

Opinion for the court filed by Circuit Judge MOORE.

Dissenting opinion filed by Circuit Judge REYNA.

MOORE, Circuit Judge.

Blackbird Tech LLC (“Blackbird”) appeals the U.S. 

District Court for the District of Delaware’s entry of 

judgment of noninfringement of claim 12 of U.S. Patent 

No. 7,086,747 (“’747 patent”) based on its construction of 

“attachment surface.” Because the court erred in construing “attachment surface,” we vacate and remand.

BACKGROUND

Blackbird owns the ’747 patent, which is directed to 

energy efficient lighting apparatuses. ’747 patent at 

Abstract, 2:24–3:16. One embodiment, illustrated in 

Figure 5 below, discloses retrofitting an existing light 

fixture with a more energy efficient lighting apparatus. 

Id. at 9:1–10:28.
BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC. 3

Id. at Fig. 5. This embodiment depicts a lighting apparatus 500, which includes a housing 528 that is dimensioned to be installed to an existing ballast cover1 (not 

shown). Id. at 9:12–16. The housing has an attachment 

surface 530 and an illumination surface 532 at opposite 

ends. Id. at 9:16–20. In “typical operation” the attachment surface is secured to the ballast cover of the existing 

light fixture through a fastening mechanism 534. Id. at 

9:16–19, 9:36–51. 

Blackbird sued ELB Electronics, Inc., ETi Solid State 

Lighting Inc., and Feit Electric Company, Inc. (collectively, “Defendants”) for infringing claim 12 of the ’747 patent. It recites:

12. An energy-efficient lighting apparatus for retrofit with an existing light fixture having a ballast 

cover, comprising:

a housing having an attachment surface

and an illumination surface;

a plurality of illumination surface holes in 

the illumination surface;

a circuit board comprising a plurality of 

light-emitting diodes, wherein the circuit 

board is positioned adjacent the housing 

so that the plurality of light-emitting diodes protrude through the plurality of illumination surface holes in the 

illumination surface; and

 

1 The specification explains that the ballast is an 

electronic component that maintains a current through 

the fluorescent lights to illuminate them. Id. at 5:1–14, 

65–67. The ballast cover conceals the ballast and other 

wiring. Id. at 5:2–4.
4 BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC.

a fastening mechanism for securing the attachment surface of the lighting apparatus 

to the illumination surface, wherein the 

lighting apparatus is coupled to a wall

switch and wherein the illumination of the 

light-emitting diodes is controllable based 

upon the position of the wall switch.

The parties disputed the meaning of “attachment surface,” specifically whether the attachment surface must be 

secured to the ballast cover. Blackbird proposed construing “attachment surface” as “layer of the housing to which 

the illumination surface is secured,” and Defendants 

proposed “layer of the housing that is secured to the 

ballast cover and to which the illumination surface is 

secured.” J.A. 7. The district court construed “attachment surface” as “layer of the housing that is secured to 

the ballast cover.” J.A. 7–9.

Following claim construction, Blackbird stipulated to 

noninfringement, and the district court entered judgment 

in favor of Defendants. Blackbird timely appeals. We 

have jurisdiction under 28 U.S.C. § 1295(a)(1).

DISCUSSION

We review claim construction based solely on intrinsic 

evidence de novo. Poly-Am., L.P. v. API Indus., Inc., 839 

F.3d 1131, 1135–36 (Fed. Cir. 2016). “The words of a 

claim are generally given their ordinary and customary 

meaning as understood by a person of ordinary skill in the 

art when read in the context of the specification and 

prosecution history.” Thorner v. Sony Comput. Entm’t 

Am. LLC, 669 F.3d 1362, 1365 (Fed. Cir. 2012).

We conclude that the district court erred in construing 

“attachment surface” to be secured to the ballast cover. 

By its plain language, claim 12 does not require the 

attachment surface to be secured to the ballast cover. 

Claim 12 expressly recites a fastening mechanism for 
BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC. 5

securing the attachment surface to the illumination 

surface. It does not refer to any other fastening mechanism. It does not require the attachment surface be 

secured to anything other than the illumination surface.

The district court nevertheless read in a second fastening mechanism—this one to secure the attachment 

surface to the ballast cover. As discussed, the specification discloses an embodiment for an energy efficient 

lighting apparatus that can be retrofitted on an existing 

fixture, and that embodiment describes a fastener that 

connects the ballast cover to the attachment surface. See, 

e.g., ’747 patent at 2:65–3:10, 9:1–10:28, Fig. 5. We do not 

agree that this fastener limitation should be imported 

into the claim. 

There is no suggestion in the specification or prosecution history that this fastener is important in any way 

that would merit reading it into claim 12. In fact, in 

describing the embodiment in Figure 5, the specification 

explains that the fastening can be achieved by “many 

different types of fastening mechanisms” including “an 

adhesive strip” (think tape), “a magnet, clips, screws, etc.” 

’747 patent at 9:40–51. It never refers to this run-of-themill fastener as the “present invention” or “an essential 

element” or uses any other language that would cause the 

ordinarily skilled artisan to believe that this fastening 

mechanism is an important component of the invention or 

that it is critical to the invention for any reason.2 See, 

 

2 This fastener is also mentioned in the “Summary 

of the Invention.” ’747 patent at 2:65–3:10. The Summary of the Invention often spans many paragraphs, 

columns, or even pages. In cases where we have held 

limitations ought to be read in, it was not simply because 

those limitations appeared in the Summary of the Invention. There was specific language that made clear those 

limitations were important to the claimed invention. See, 
6 BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC.

e.g., Luminara Worldwide, LLC v. Liown Elecs. Co., 814 

F.3d 1343, 1353 (Fed. Cir. 2016) (noting we have found 

disavowal or disclaimer based on statements such as “the 

present invention includes” or “the present invention is”); 

X2Y Attenuators, LLC v. Int’l Trade Comm’n, 757 F.3d 

1358, 1362 (Fed. Cir. 2014) (noting we have held labeling 

an embodiment or element as “essential” may constitute 

disavowal and finding disavowal where the specification 

stated a disclosure was an “essential element among all 

embodiments or connotations of the invention”); Regents 

of Univ. of Minn., 717 F.3d at 936 (finding disavowal 

where the specification used the phrase “[t]he present 

invention”); Verizon Servs. Corp. v. Vonage Holdings 

Corp., 503 F.3d 1295, 1308 (Fed. Cir. 2007) (same); Honeywell Int’l, Inc. v. ITT Indus., Inc., 452 F.3d 1312, 1318 

(Fed. Cir. 2006) (same); SciMed Life Sys., Inc. v. Advanced 

Cardiovascular Sys., Inc., 242 F.3d 1337, 1343–45 (Fed. 

Cir. 2001) (same and “all embodiments of the present 

invention”). We cannot discern, nor does any party argue 

that there is, a technologically significant reason to have 

the fastening mechanism secure the attachment surface 

to the ballast cover. At oral argument, a number of 

different, technologically unsophisticated mechanisms for 

fastening were discussed. Oral Arg. at 20:10–20:35, 

21:28–22:14. No party argued that the fastening mechanism securing the attachment surface to the ballast cover 

was an important feature of the claimed invention. Nor is 

there any such suggestion in either the intrinsic or extrinsic evidence. To the contrary, the specification explains 

the embodiment in Figure 5 is exemplary and nonlimiting. ’747 patent at 4:16–27, 10:29–32. It also explains that it is in “typical operation” that the attachment 

 

e.g., Regents of Univ. of Minn. v. AGA Med. Corp., 717 

F.3d 929, 936 (Fed. Cir. 2013) (finding disclosures in the 

Summary of the Invention limiting where directed to 

“[t]he present invention”). 
BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC. 7

surface is secured to the ballast cover. Id. at 9:17–19. It 

simply cannot be the case that every screw mentioned in 

an embodiment of the specification must be read into the 

claim. Without any evidence that the fastener is important, essential, or critical to the invention, it should 

not be read in as a claim limitation. 

And possibly the most important reason why the fastener for connecting the attachment surface to the ballast 

cover disclosed in an embodiment ought not be imported 

into the claim is because that limitation was originally 

present in claim 12 and was expressly eliminated during 

prosecution. Claim 12 was initially rejected under 35 

U.S.C. § 102(b), and the applicant made responsive 

amendments not relevant here. The examiner then had 

an interview with the applicant. He prepared the examiner’s summary of the interview, which stated the applicant agreed to amend claim 12 “to resolve 112 issues.” 

J.A. 56. That amendment deleted “ballast cover” and 

replaced it with “illumination surface.” J.A. 54. That is, 

the applicant expressly eliminated from the claim a 

fastening mechanism that secures the attachment surface 

to the ballast cover and replaced it with a fastening 

mechanism that secures the attachment surface to the 

illumination surface. The claim was allowed. No ordinary artisan could read the prosecution history as anything other than eliminating the requirement that a

fastening mechanism secures the attachment surface to 

the ballast cover. No other possible reason was suggested 

or alleged in this case. 

Defendants argue the prosecution history is ambiguous because the examiner’s requirement that the change 

be made “to resolve [§] 112 issues” provides no explanation for the amendment. This argument is both factually 

incorrect and legally irrelevant to how a skilled artisan 

reading this history would understand the claim scope. 

The examiner stated, and the applicant never contradicted, that the amendment was required for § 112 reasons. 
8 BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC.

Any skilled artisan would understand that if an examiner 

requires an amendment for § 112 reasons it is an amendment required for patentability. As a factual matter, no 

skilled artisan would understand this claim to require a 

fastening mechanism connecting the ballast cover to the 

attachment surface when that very limitation was expressly removed from the claim to secure patentability 

with the examiner’s blessing and agreement. We review 

the prosecution history from the perspective of an ordinary artisan and what he would understand from its 

contents. The only takeaway here is that claim 12 needs

a fastening mechanism to secure the attachment surface 

to the illumination surface, not to the ballast cover,

because this was the only change made at the examiner’s 

request for § 112 reasons. A person of ordinary skill in 

the art may not be able to divine what transpired between 

the applicant and the examiner in that interview that 

caused the change in claim language and scope. That is

irrelevant to the issue. We look at what an ordinarily

skilled artisan would understand about claim scope from 

reading the prosecution history. See, e.g., Fenner Invs., 

Ltd. v. Cellco P’ship, 778 F.3d 1320, 1323 (Fed. Cir. 2015)

(“Any explanation, elaboration, or qualification presented 

by the inventor during patent examination is relevant, for 

the role of claim construction is to ‘capture the scope of the 

actual invention’ that is disclosed, described, and patented.” (emphases added)); Biogen Idec, Inc. v. GlaxoSmithKline LLC, 713 F.3d 1090, 1095 (Fed. Cir. 2013)

(“[T]he entirety of a patent’s file history captures the 

public record of the patentee’s representations concerning 

the scope and meaning of the claims.”); Hynix Semiconductor Inc. v. Rambus Inc., 645 F.3d 1336, 1350 (Fed. Cir. 

2011) (“Phillips counsels looking to the prosecution history to ‘show what a person of skill in the art would have 

understood disputed claim language to mean.’”); Arachnid, Inc. v. Medalist Mktg. Corp., 972 F.2d 1300, 1302 

(Fed. Cir. 1992) (noting that claim scope is determined by 

examining the prosecution history). And here, without 
BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC. 9

question, the requirement that the invention as claimed 

requires a fastening mechanism for securing the attachment surface to the ballast cover was undisputedly and

unequivocally deleted from the claim. 

Defendants argue the preamble, “[a]n energy-efficient 

lighting apparatus for retrofit with an existing light 

fixture having a ballast cover,” requires reading in the 

disclosed fastener for the claim to achieve its “retrofit” 

function. A requirement such as this, according to Defendants, is sufficient not only to read into a claim a 

limitation that is not present, but also to read into the 

claim the precise mechanism by which that retrofitting 

shall be achieved. The only claim at issue is claim 12, and 

it is an apparatus, not a method claim. The apparatus 

disclosed in claim 12 is structurally complete as claimed. 

An apparatus claim is not required to include all elements 

necessary for the claimed structure’s installation. This 

claim does not recite how the lighting apparatus is installed into an existing light fixture, and it is not required 

to do so. 

We have considered Defendants’ remaining arguments and find them unpersuasive.

CONCLUSION

We conclude the district court erred in construing “attachment surface,” and adopt Blackbird’s construction of 

“layer of the housing to which the illumination surface is 

secured.” Because the court’s entry of judgment of noninfringement was based on its erroneous construction, we 

vacate the entry of judgment and remand for further 

proceedings.

VACATED AND REMANDED

COSTS

Costs to Blackbird.
United States Court of Appeals 

for the Federal Circuit ______________________

BLACKBIRD TECH LLC, DBA BLACKBIRD 

TECHNOLOGIES,

Plaintiff-Appellant

v.

ELB ELECTRONICS, INC., ETI SOLID STATE 

LIGHTING INC., FEIT ELECTRIC COMPANY INC.,

Defendants-Appellees

______________________

2017-1703

______________________

Appeal from the United States District Court for the 

District of Delaware in Nos. 1:15-cv-00056-RGA, 1:15-cv00057-RGA, 1:15-cv-00058-RGA, 1:15-cv-00062-RGA, 

Judge Richard G. Andrews.

______________________

REYNA, Circuit Judge, dissenting.

The sole issue on appeal is whether the “attachment 

surface” in claim 12 must be secured to the ballast cover 

of the existing light fixture. Because I conclude that the 

district court correctly construed “attachment surface” to 

mean “layer of the housing that is secured to the ballast 

cover,” I respectfully dissent. 

Claim 12 does not expressly require that the attachment surface be attached to anything other than to the 

illumination surface. However, claim 12 does expressly 
2 BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC.

describe a lighting apparatus “for retrofit with an existing 

light fixture having a ballast cover.” ’747 patent col. 11 ll. 

26–27 (emphases added). The majority fails to give 

meaning to these claim terms by holding that “attachment surface” means “layer of the housing to which the 

illumination surface is secured,” and concludes that the 

patent owner is entitled to patent scope that is neither 

described in nor supported by the specification. 

The plain language of claim 12, read in the context of 

the specification, implicitly requires that the attachment 

surface be secured to the ballast cover to achieve the 

retrofit function. Apart from the preamble, which the 

parties agree is limiting, claim 12 contains no reference to 

the ballast cover, the existing light fixture, or where or 

how the apparatus is retrofit with the existing light 

fixture. Because the only feature of the existing light 

fixture described in claim 12 is the ballast cover, a person 

of ordinary skill would necessarily conclude that the 

attachment surface is secured to the ballast cover of the 

existing light fixture. This would not be a big leap. 

The disputed term “attachment surface” appears only 

in claims related to the retrofit function—namely claim 

12, the disputed claim, claim 29, which describes a method for retrofitting a light fixture, and various associated 

dependent claims. As the word “retrofit” in the preamble 

of claim 12 implies securing the lighting apparatus to 

something, it is reasonable to conclude that the “attachment surface” is involved with achieving the retrofit 

function. 

The structure of the claim language gives further 

support that the “attachment surface” has a function 

associated with the retrofit function. Along with the 

“illumination surface,” the attachment surface is one of 

two identified surfaces of the lighting apparatus’s housing, and is secured to the illumination surface via a 
BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC. 3

fastening mechanism. See id. col. 11 ll. 28–29, 37–39. 

The illumination surface has an explicit function in 

addition to simply being secured to the attachment surface, suggesting that the attachment surface likewise has 

an additional “attachment” function other than attachment to the illumination surface. See id. col. 11 ll. 30–31. 

Every single embodiment of the retrofit lighting apparatus in the specification describes securing the attachment surface to the ballast cover of the existing light 

fixture. The specification expressly discloses retrofitting 

by securing the attachment surface to the ballast cover in 

the summary of the invention, see ’747 patent col. 2 l. 65–

col. 3 l. 10; col. 3 ll. 46–49 (describing “[a] method for 

retrofitting a light fixture with an energy-efficient lighting apparatus,” in which “[t]he method also involves 

securing the attachment surface of the housing to the 

ballast cover” (emphasis added)), and in the embodiment 

disclosed in connection with Figure 5, see id. col. 9 ll. 8–

10. In describing Figure 5, the specification states that 

“[i]n typical operation, the attachment surface 530 is 

secured to the ballast cover.” Id. col. 9 ll. 17–19. The

specification provides no other explanation for how the 

lighting apparatus may be retrofit to the existing light 

fixture. Taken collectively, these disclosures in the claims 

and the specification—and the lack of any reference in the 

intrinsic record showing the attachment surface being 

secured to anything other than the ballast cover—teach a 

skilled artisan that the attachment surface described in 

claim 12 is secured to the ballast cover of the existing 

light fixture. See MBO Labs., Inc. v. Becton, Dickinson & 

Co., 474 F.3d 1323, 1329 (Fed. Cir. 2007) (“The words of 

patent claims have the meaning and scope with which 

they are used in the specification and the prosecution 

history.”).

The majority ignores the retrofit function that the attachment surface plays in the lighting apparatus. See 
4 BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC.

Medrad, Inc. v. MRI Devices Corp., 401 F.3d 1313, 1319 

(Fed. Cir. 2005) (“It is . . . entirely proper to consider the 

functions of an invention in seeking to determine the 

meaning of particular claim language.”). Instead of 

recognizing the attachment surface as it is described 

throughout the specification—namely, to secure the 

lighting apparatus to the ballast cover—the majority’s 

construction merely parrots features of the attachment 

surface, i.e., that it is attached to the illumination surface.

In doing so, the majority fails to give meaning to “attached” beyond what is already described in the claim 

language. See Apple, Inc. v. Ameranth, Inc., 842 F.3d 

1229, 1237 (Fed. Cir. 2016) (“Ideally, claim constructions 

give meaning to all of a claim’s terms.”). The majority’s 

construction completely disregards the context in which 

“attachment surface” is used, both in connection with the 

retrofit function and the embodiments described in the 

specification. The majority does not point to anything in 

the specification describing a retrofit apparatus in which 

the attachment surface is not secured to the ballast cover. 

And there is no suggestion in the record that such an 

embodiment was ever contemplated or possessed by the 

inventor. 

The majority’s construction thus opens the door for 

the ’747 patent to be subsequently invalidated for failure 

to satisfy the written description requirement. Stated 

differently, the majority’s construction is a route towards 

rendering the patent invalid. See Carman Indus., Inc. v. 

Wahl, 724 F.2d 932, 937 (Fed. Cir. 1983) (“Claims should 

be so construed, if possible, as to sustain their validity. If 

such a construction would result in invalidity of the 

claims, the appropriate legal conclusion is one of noninfringement, not invalidity.”). The majority likewise 

invites an enablement challenge; under the majority’s 

approach, the retrofit aspect of the invention is merely an 

afterthought, one for which a skilled artisan must figure 
BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC. 5

out for themselves the means by which the retrofit function of the invention shall be achieved, without any guidance from the patent. See Maj. Op. at 9. This result is 

absurd, given that when the patent is read as a whole, 

such guidance is clearly provided.

Worse still, because the majority’s construction “does 

not recite how the lighting apparatus is installed into an 

existing light fixture,” id., the majority effectively reads 

the retrofit function out of claim 12 and claim 29, the 

retrofitting method claim. Claim 29, while not at issue in 

this case, is instructive. See Phillips v. AWH Corp., 415 

F.3d 1303, 1314 (Fed. Cir. 2005) (en banc) (“Because claim 

terms are normally used consistently throughout the 

patent, the usage of a term in one claim can often illuminate the meaning of the same term in other claims.”). 

Claim 29 contains the same “attachment surface” limitation at issue in claim 12: 

29. A method for retrofitting a light fixture with 

an energy-efficient lighting apparatus, the light 

fixture having a ballast cover, the method comprising:

providing a housing having an attachment 

surface and an illumination surface, wherein the 

illumination surface comprises a plurality of illumination surface holes;

providing a circuit board comprising a plurality of light-emitting diodes;

positioning the circuit board adjacent the 

housing so that the plurality of light-emitting diodes protrude through the plurality of illumination surface holes in the illumination surface; and

securing the attachment surface of the housing to the illumination surface, wherein the lighting apparatus is coupled to a wall switch and 
6 BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC.

wherein the illumination of the light-emitting diodes is controllable based upon the position of the 

wall switch.

’747 patent, col. 12 ll. 52–60 (emphasis added). 

We cannot discount the importance of the retrofit aspect to the invention as a whole. The specification clearly 

details the importance of retrofitting energy-efficient 

lighting apparatuses into preexisting light fixtures as a 

means of achieving energy savings without incurring 

significant expense. ’747 patent, col. 9 ll. 5–10; col. 10 ll. 

6–9. Yet the majority contends that claim 12, as an 

apparatus claim, is structurally complete as construed 

and need not describe the method of installation. Maj. 

Op. at 9. But because the majority’s construction does not 

disclose how the apparatus is installed, securing the 

retrofit apparatus to the preexisting light fixture falls 

outside of the scope of the claims. If “attachment surface” 

is not construed as being secured to the ballast cover, 

claim 29 utterly fails to disclose how the retrofit function 

is to be achieved. As the district court properly noted 

during the Markman hearing, the lighting apparatus for 

retrofit “ha[s] to be attached to something” and cannot 

“hover . . . like a ghost.” J.A. 254. 

The majority’s reliance on the prosecution history is 

similarly misplaced. The prosecution history “can often 

inform the meaning of the claim language by demonstrating how the inventor understood the invention” but “lacks 

the clarity of the specification and thus is less useful for 

claim construction purposes.” Phillips, 415 F.3d at 1317; 

see also Grober v. Mako Prods., Inc., 686 F.3d 1335, 1341 

(Fed. Cir. 2012) (“[W]hile the prosecution history can 

inform whether the inventor limited the claim scope in 

the course of prosecution, it often produces ambiguities 

created by ongoing negotiations between the inventor and 

the PTO.”). The original claim 12 reveals that, prior to 
BLACKBIRD TECH LLC v. ELB ELECTRONICS, INC. 7

amendment, the applicant understood that the invention 

requires the attachment surface to be secured to the 

ballast cover. See Phillips, 415 F.3d at 1317. Apart from 

the amendment itself, the prosecution history sheds no 

light on the purpose or effect of the amendment on claim 

scope. I conclude that the amendment is ambiguous as to 

the scope of the disputed limitation and has no effect on 

the proper construction of “attachment surface” in claim 

12. An ambiguous amendment, such as here, should not 

negate the evidence in the specification and the conclusion implicit in the claim language that the attachment 

surface is secured to the ballast cover. 

Because the intrinsic record fully supports the construction of attachment surface as being secured to the 

ballast cover, I respectfully dissent.