Exhibit 12.1

Sensata Technologies B.V.

Computation of Ratio of Earnings To Fixed Charges

(dollars in thousands)

(Unaudited)



|                                                             |  |                 |         |                 |           |                                           |  |   |                                             |  |  |                 |          |   |                 |   |          |   |  |   |         |  
|------------------------------------------------------------ |  | --------------- | ------- | --------------- | --------- | ----------------------------------------- |  | - | ------------------------------------------- |  |  | --------------- | -------- | - | --------------- | - | -------- | - |  | - | ------- | -
|                                                             |  | Predecessor     |         |                 | Successor |                                          
|                                                             |  | 2004(Unaudited) |         | 2005(Unaudited) |           | January 1,2006 - April26, 2006(Unaudited) |  |   | April 27, 2006 -December 31,2006(Unaudited) |  |  | 2007(Unaudited) |          |   | 2008(Unaudited) |  
|Income/(loss) from continuing operations before income taxes |  | $               | 235,446 |                 | $         | 225,731                                   |  | $ | 71,333                                      |  |  | $               | (162,435 | ) |                 | $ | (171,745 | ) |  | $ | (60,870 | )
|Add: Fixed Charges                                           |  |                 | 810     |                 |           | 1,090                                     |  |   | 1,143                                       |  |  |                 | 166,079  |   |                 |   | 192,968  |   |  |   | 200,325 |  
|                                                             |  |                 |         |                 |           |                                           |  |   |                                             |  |  |                 |          |   |                 |   |          |   |  |   |         |  
|Total Earnings                                               |  | $               | 236,256 |                 | $         | 226,821                                   |  | $ | 72,476                                      |  |  | $               | 3,644    |   |                 | $ | 21,223   |   |  | $ | 139,455 |  
|                                                             |  |                 |         |                 |           |                                          
|Fixed charges:                                               |  |                 |         |                 |           |                                           |  |   |                                             |  |  |                 |          |   |                 |   |          |   |  |   |         |  
|Interest expense                                             |  |                 |        |                 |           | 105                                       |  |   | 511                                         |  |  |                 | 153,642  |   |                 |   | 181,521  |   |  |   | 187,143 |  
|Amortization of debt issuance cost                           |  |                 |        |                 |           |                                          |  |   |                                            |  |  |                 | 11,518   |   |                 |   | 9,640    |   |  |   | 10,697  |  
|Portion of rent expense estimated to represent interest(1)   |  |                 | 810     |                 |           | 985                                       |  |   | 632                                         |  |  |                 | 919      |   |                 |   | 1,807    |   |  |   | 2,485   |  
|                                                             |  |                 |         |                 |           |                                           |  |   |                                             |  |  |                 |          |   |                 |   |          |   |  |   |         |  
|Total fixed charges                                          |  | $               | 810     |                 | $         | 1,090                                     |  | $ | 1,143                                       |  |  | $               | 166,079  |   |                 | $ | 192,968  |   |  | $ | 200,325 |  
|                                                             |  |                 |         |                 |           |                                           |  |   |                                             |  |  |                 |          |   |                 |   |          |   |  |   |         |  
|Ratio of earnings to fixed charges                           |  |                 | 291.7   |                 |           | 208.1                                     |  |   | 63.4                                        |  |  |                 | NM       |   |                 |   | NM       |   |  |   | NM      |  



|(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 the period
April 27, 2006 to December 31, 2006 and the fiscal years 2007 and 2008 of $162,435, $171,745 and $60,870, respectively, to achieve a coverage of 1:1.