These sensors are Genuine Not a Counterfiet manufactured by Schrader Electronics in United Kingdom. They are made with high quality materials and components to strict Certificates Standards. All sensor fittings made from aluminum. Each sensor has Original marking Made by Schrader Electronics. With this set you will always know the level of air in your trailer tires with this set of Chevrolet Accessories Trailer Tire Pressure Monitor (TPM) Sensors. Designed for use on Chevrolet Silverado and GMC Sierra Models with RPO (Regular Production Option) Codes PTT (Trailer Tire Pressure Monitor Sensors)or U1D (Advanced Trailering System), these TPM Sensors are synced to the vehicle Infotainment System and notify you when any of your trailer tires are low on pressure. Sensor Stem size standard. Reading pressure range up to 148 psi. 1 Designed, Engineered, Tested and Backed by GM. 2 Genuine GM Accessories provide Factory Fit and Finish. 3 Monitors trailer tire pressure and informs driver when pressure levels are low. 4 Set of Four (4) Trailer Tire Pressure Monitor Sensors. 5 For Use on Models with RPO Code PTT or U1D. You will receive 4 sensors in a package same as in pictures above. They are new never used. The functionality and compatibility is unchanged (tire pressure and temperature). Make Model Year Trim. Chevrolet Silverado 1500 2019-24 High Country, LT, LT Tail Boss, LTZ, RST. 5.3L, 6.2L Gas. GMC Sierra 1500 2020-24 SLT, AT4, Denali. Chevrolet Silverado 2500 HD 2020-24 LT, LTZ, High Country. 6.6L Diesel T. Chevrolet Silverado 3500 HD 2020-24 LT, LTZ, High Country. GMC Sierra 2500 HD 2020-24 SLT, AT4, Denali. GMC Sierrs 3500 HD 2020-24 SLT, AT4, Denali. Chevrolet Tahoe 2021-24 Z71, Premier, High Country. GMC Yukon 2021-24 SLT, AT4, Denali.