Main functions: 1. Tire pressure and tire temperature display on all four wheels simultaneously 2. Abnormal tire pressure and temperature alarm, Tire pressure above 3.2 bar (default) alarm Tire pressure below 1.8 bar (default) alarm Tire temperature above 68 (default) alarm The default value can be adjusted according to actual needs 3. This product detector is only applicable to Android system's in car multimedia. Parameters: Receiver parameters Receiving frequency: 433.92MHz Power supply method: USB power supply, solar power supply Working voltage: DC 5V Pressure unit: bar/psi Temperature unit: / Working temperature: -20 to 85 Storage temperature: -40--105 Built-in sensor parameters Transmission frequency: 433.92MHz Pressure range: 0-3.5 bar/0-6 bar Default low pressure alarm value: 1.8 bar Default high pressure alarm value: 3.2 bar Pressure accuracy: 0.1 bar/ 1bar Working voltage: DC+2.0-3.6V Working temperature: -20 to 85 Storage temperature: -40 to 125 Waterproof level: IP67 Battery: built-in CR2050 button battery Battery life: 3-5 years External sensor parameters Transmission frequency: 433.92MHz Pressure range: 0-3.5 bar/0-6 bar Default low pressure alarm value: 1.8 bar Default high pressure alarm value: 3.2 bar Pressure accuracy: 0.1 bar/ 1bar Working voltage: DC+2.0-3.6V Working temperature: -20 to 85 Storage temperature: -40 to 125 Waterproof level: IP67 Battery: Built in CR1632 button battery (can be disassembled and replaced by oneself) Battery life: 1.5-2 years typical value Packaging list 1: 1 * Receiver 4 * external tire pressure sensors 1 * Instructions 1 * Wrench 4 * Anti theft nut Packaging List 2: 1 * Receiver 4 * built-in tire pressure sensors 1 * Instructions 1 * Allen wrench