Exhibit 12.1

Sensata Technologies B.V.

Computation of Ratio of Earnings To Fixed
Charges

(dollars in thousands)

(Unaudited)



|                                                           |  |           |         |  |                               |   |         |      |  |   |         |   |  |                                                      |          |   |  |   |          |   |  |   |        | 
|---------------------------------------------------------- |  | --------- | ------- |  | ----------------------------- | - | ------- | ---- |  | - | ------- | - |  | ---------------------------------------------------- | -------- | - |  | - | -------- | - |  | - | ------ | 
|                                                           |  | Successor |         |  | Predecessor                   |  
|                                                           |  |           |         |  | January 1,2006 -April 26,2006 |  
|                                                           |  | 2010      |         |  | 2009                          |   |         | 2008 |  |   | 2007    |   |  | For the periodApril 27(inception) toDecember 31,2006 |          |  
|Income from continuing operations                          |  | $         | 169,689 |  |                               | $ | 16,453  |      |  | $ | (60,870 | ) |  | $                                                    | (171,745 | ) |  | $ | (162,435 | ) |  | $ | 71,333 | 
|Add: Fixed Charges                                         |  |           | 107,818 |  |                               |   | 152,164 |      |  |   | 200,325 |   |  |                                                      | 192,968  |   |  |   | 166,079  |   |  |   | 1,143  | 
|                                                           |  |           |         |  |                               |   |         |      |  |   |         |   |  |                                                      |          |   |  |   |          |   |  |   |        | 
|Total Earnings                                             |  | $         | 277,507 |  |                               | $ | 168,617 |      |  | $ | 139,455 |   |  | $                                                    | 21,223   |   |  | $ | 3,644    |   |  | $ | 72,476 | 
|                                                           |  |           |         |  |                               |   |         |      |  |   |         |   |  |                                                      |          |   |  |   |          |   |  |   |        | 
|                                                           |  |           |         |  |                               |  
|Fixed charges:                                             |  |           |         |  |                               |   |         |      |  |   |         |   |  |                                                      |          |   |  |   |          |   |  |   |        | 
|Interest expense                                           |  |           | 97,836  |  |                               |   | 141,534 |      |  |   | 187,142 |   |  |                                                      | 181,521  |   |  |   | 153,642  |   |  |   | 511    | 
|Amortization of debt issuance cost                         |  |           | 8,564   |  |                               |   | 9,055   |      |  |   | 10,698  |   |  |                                                      | 9,640    |   |  |   | 11,518   |   |  |   |       | 
|Portion of rent expense estimated to represent interest(1) |  |           | 1,418   |  |                               |   | 1,575   |      |  |   | 2,485   |   |  |                                                      | 1,807    |   |  |   | 919      |   |  |   | 632    | 
|                                                           |  |           |         |  |                               |   |         |      |  |   |         |   |  |                                                      |          |   |  |   |          |   |  |   |        | 
|Total fixed charges                                        |  | $         | 107,818 |  |                               | $ | 152,164 |      |  | $ | 200,325 |   |  | $                                                    | 192,968  |   |  | $ | 166,079  |   |  | $ | 1,143  | 
|                                                           |  |           |         |  |                               |   |         |      |  |   |         |   |  |                                                      |          |   |  |   |          |   |  |   |        | 
|Ratio of earnings to fixed charges                         |  |           | 2.6     |  |                               |   | 1.1     |      |  |   | NM      |   |  |                                                      | NM       |   |  |   | NM       |   |  |   | 63.4   | 



|(1) | Represents approximately one-third of rent expense which is deemed to represent the interest component of rental payments.
|--- | --------------------------------------------------------------------------------------------------------------------------

NM - Due to the registrants loss in the successor periods, the ratio coverage was less than 1:1 The registrants earnings for the years ended
December 31, 2008 and 2007 and the period from April 27, 2006 (inception) to December 31, 2006 were insufficient to cover its fixed charges and achieve a coverage ratio of 1:1 by $60,870, $171,745 and $162,435, respectively.