Set of (1) Schrader EZ Sensor 33500 with rubber valve stems. Will work on OEM & aftermarket wheels. Fits the most vehicles: REQUIRES PROGRAMMING WITH A CAPABLE TPMS TOOL!!!! The battery-powered TPMS sensor monitors a vehicle? S tire pressure, whether the vehicle is stationary or in motion. The sensor is attached to the vehicle? S tire valve stem, with the sensing electronics inside the tire. The sensor periodically measures tire pressure and temperature and transmits this information to an on-board receiver via radio frequency (RF) technology. The receiver decodes the RF signals, and alerts the driver if any of the vehicle? S tire pressures drop below a pre-programmed threshold.