There is a large amount of FAKE Chinese TPMS products coming into the US market. Buyer BEWARE! These products may appear visually similar however the electronics, battery, and materials are significantly different. Tire Pressure Monitoring Sensors are a safety device. No one should take chances with non validated, untested parts. This puts drivers as well as passengers at risk. Look for obvious signs on the product:
-DOES THE PART HAVE AN FCC ID? CMIIT IS A CHINA ID NUMBER, NO FCC ID MEANS ITS NOT LEGAL TO USE IN THE USA!!!
-Does it appear sub standard quality?
-Are words and manufactures names misspelled?
-Is it labeled with country of origin?
Its always best to buy from reputable resellers that you can verify work with OEM suppliers!
Source: The TPMS Forum