The pressure is checked by the sensor installed inside the rim, not the valve cap!
Steelmate tire pressure sensor for replacement or if you want additional sensors for the Steelmate TPMS system (eg winter tires/summer tires).
Not suitable for the car's original tire pressure systems.

Operating frequency: 433.92 MHz
Voltage: 2.0~3.6V
Temperature tolerance: -40℃~+125℃
Temperature reading accuracy: ±1℃
Pressure reading accuracy: ±0.1Bar
Sensor battery life: ~5 years