Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Does this fit a Honeywell 17000 and if so does just one fit or do you need two?
Document: Honeywell has decided that we can sandwich two of their smaller filters together to replace the single large HEPA filter that came with the 17000 product, and I do not see how that "seam" (and it's rather a wide seam, where the edges of two smaller filters fit together) can possibly be filtering anything at all, so you are no longer getting the same amount of filtration thanks to that.
First of all this is NOT a Honeywell product. Second, is a cheaply made after-market replacement that most likely will not properly fit your air cleaner, leading to a lot of noise and a lot of dirt being blown back into the air. The reason that these are being sold is that Honeywell, instead of continuing to manufacture several sizes of filter to fit their assorted air cleaners, went to a modular system. Your Honeywell machine will take either one, two or three of the smaller modules.
Before ordering a replacement HEPA filter for your Honeywell (or other brand) Air Cleaner, be sure to check the model number on the unit. This filter is for the smaller round unit (Model 10500) and for the smaller of the two upright units with handles (Model 17000). I replace my HEPA filter every year because I am very allergic to cigarette smoke, pollens, dust, molds, and other allergens and irritants.
Listed as a direct fit for the Honeywell 17000 but is not the exact right size. It is wider than the original filter so when you install it the lid will stick out a bit once screwed in.
Got this replacement filter for model 17000 Honeywell HEPA Air Purifier, fit like a glove inside the unit, with tight seal.
The first Honeywell air filter HEPA pre-filter I ordered was through Amazon and its site that sounds like a drug store name. It was the wrong filter and it would have taken two that size to accommodate the air cleaner it was supposed to fit, but it was priced like the ones twice its size. It arrived in a box that looked very very tired. My thought was that, in addition to the box, the filter might have been well traveled, too, because it seemed like a deceptive practice.
This is not made by Honeywell as they do not make a single unit filter for these air purifiers. Honeywell requires you to purchase two smaller filters that you put together, which also costs a lot more. This filter fits perfectly and works like it is supposed to. I had bought one 2 years ago and it was time to replace it.
This filter was supposed to fit my Honeywell air filter, but it doesn't. I called the mfg, they offered little help--even after I sent them photos of the difference b/t the filter they sent and the one being replaced (thier's was about 1/16" to narrow--which is a lot for air passage). They did offer to refund 20% of the price, but that barely covered shipping. Bummer.
I've been using honeywell enviracaire hepa filters for years. I used to always buy the genuine OEM filter. But apparently that has been discontinued. You can get the small OEM filters and combine 2 or 3 to fit. But if you want just one piece, honeywell enviracaire no longer makes that size. You have to go to generic aftermarket filters now.I bought one on Amazon from Filters-Now.
Actually white matches the unit better than the black one did...The shipping company on the other hand, I'm none too pleased with. Fedex SmartPost has got to be the slowest, shoddiest option I've experienced. This isn't the vendor's fault (SmartPost packages have a very strange roundabout method of transportation) but if you're hoping for next day air you'll need a bit more patience.
Answer: The short answer is NO.  Honeywell no longer makes this filter, and what is advertized as an Enviracare 20500 "by Honeywell" is actually a cheaply made product from an after-market manufacturer. The few I bought were shoddily made and did not fit exactly, so that they were noisy, leaked air, and did a poor job of filtering.  Honeywell went to a modular system, making, among others, a smaller stackable filter called the HRF-D1.  Depending on the model of your air cleaner, one to three filters are needed.  My 17000 takes two of the HRF-D1 stacked on top of one another.  They are quite obviously more carefully made, and quiet in operation, and they clean the air.  By the way, buy the "real" Honeywell prefilters as well -- HRF-AP1.  They work much better than the no-name replacements that are offered.