Exhibit 12.1

Sensata Technologies B.V.

Computation of Ratio of
Earnings To Fixed Charges

(dollars in thousands)

(Unaudited)



|                                                             |  |                                 |         |      |                                                      |         |      |                                        |   |          |   |  |   |          |   |  |   |       
|------------------------------------------------------------ |  | ------------------------------- | ------- | ---- | ---------------------------------------------------- | ------- | ---- | -------------------------------------- | - | -------- | - |  | - | -------- | - |  | - | ------
|                                                             |  | Successor                       |         |      | Predecessor                                         
|                                                             |  | For the year ended December 31, |         |      | For the periodApril 27(inception) toDecember 31,2006 |         |      | For the periodJanuary 1toApril 26,2006
|                                                             |  | 2009                            |         | 2008 |                                                      |         | 2007 |                                        |   |         
|Income/(loss) from continuing operations before income taxes |  | $                               | 16,453  |      | $                                                    | (60,870 | )    |                                        | $ | (171,745 | ) |  | $ | (162,435 | ) |  | $ | 71,333
|Add: Fixed charges                                           |  |                                 | 152,164 |      |                                                      | 200,325 |      |                                        |   | 192,968  |   |  |   | 166,079  |   |  |   | 1,143 
|                                                             |  |                                 |         |      |                                                      |         |      |                                        |   |          |   |  |   |          |   |  |   |       
|Total earnings                                               |  | $                               | 168,617 |      | $                                                    | 139,455 |      |                                        | $ | 21,223   |   |  | $ | 3,644    |   |  | $ | 72,476
|                                                             |  |                                 |         |      |                                                     
|Fixed charges:                                               |  |                                 |         |      |                                                      |         |      |                                        |   |          |   |  |   |          |   |  |   |       
|Interest expense                                             |  |                                 | 141,534 |      |                                                      | 187,142 |      |                                        |   | 181,521  |   |  |   | 153,642  |   |  |   | 511   
|Amortization of debt issuance costs                          |  |                                 | 9,055   |      |                                                      | 10,698  |      |                                        |   | 9,640    |   |  |   | 11,518   |   |  |   |      
|Portion of rent expense estimated to represent interest(1)   |  |                                 | 1,575   |      |                                                      | 2,485   |      |                                        |   | 1,807    |   |  |   | 919      |   |  |   | 632   
|                                                             |  |                                 |         |      |                                                      |         |      |                                        |   |          |   |  |   |          |   |  |   |       
|Total fixed charges                                          |  | $                               | 152,164 |      | $                                                    | 200,325 |      |                                        | $ | 192,968  |   |  | $ | 166,079  |   |  | $ | 1,143 
|                                                             |  |                                 |         |      |                                                      |         |      |                                        |   |          |   |  |   |          |   |  |   |       
|Ratio of earnings to fixed charges                           |  |                                 | 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 must
generate additional earnings for years ended December 31, 2008 and 2007 and the period from April 27, 2006 (inception) to December 31, 2006 of $60,870, $171,745 and $162,435, respectively, to achieve a coverage of 1:1.