Feature 1, Powered by solar energy, it comes with 4 external sensors. 2, LCD digital displaying, clear to show tire information. 3, Comes with an extra mini USB port, can be charged many time. 4, Rear-time monitoring pressure & temperature of 4 tires at the same time. 5, Each sensor has a separate ID code. The tire position can be interchanged.Features: Powered by solar energy, it comes with 4 external sensors. LCD digital displaying, clear to show tire information. Comes with an extra mini USB port, can be charged many time. Rear-time monitoring pressure & temperature of 4 tires at the same time. Each sensor has a separate ID code. The tire position can be interchanged. Fuel-saving, predicting air leakage, extending tire service life. Temperature explosion-proof battery, long-lasting power, more accurate monitoring data. Specification: Model: U902L-WF Monitor: Working Temperature: -20 ~ +80 Storage Temperature: -30 ~ +85 Input Voltage: DC 5V Transmitting Frequency: 433.92MHz Size: 88 * 68 * 25mm/3.5 * 2.7 * 1.0inch External Sensor: Working Temperature: -40 ~ +105 Storage Temperature: -40 ~ +120 Pressure Measurement Range: 0~116psi(0-8bar) Pressure Accuracy: 1.5PSI0.1bar Temperature Accuracy: 3 Transmitting Power: <10dbm@50 Transmitting Frequency: 433.92MHz Battery Life-span: >2 years Size(D*H): 23 * 15mm/0.9 * 0.6inch Material: ABS Plastic Color: Shown as Picture Package Weight: approx.349g/12.3oz Package list: 1 * Monitor 4 * External Sensors 1 * Fixer 1 * Bracket 1 * Power Cable 1 * Spanner 1 * Set of Screws 1 * User Manual