Product choice: Black: external black Silver: External Silver Gray: Internal gray Product Features: 1. Powered by USB cable,2 external 2. Built-in high temperature resistant explosion-proof lithium battery,fast charging, long lasting power 3. Real-time display of highly accurate tire temperature and pressure data of 2 wheels at the same time 4. Quickly detect leak and alarm, extend tire life, balance Vehicle Sensors Tire Pressure, ensure the safety of motorcycles 5.PSI, BAR two kinds of pressure unit optional, and two kinds of temperature unit optional 6. Each has a separate ID code, which has been completed before delivery, can be directly used after installation 7.dedicated radio frequency technology, the real-time updates data, alarm when Vehicle Sensors Tire Pressure and temperature are abnormal 8.dedicated Freescale chip program, 6-in-1, makes the signal more stable and reliable, monitoring data more accurate to ensure traffic safety Display parameters: Size: about 48 * 48 * 27MM/1.89 * 1.89 * 1.06in Weight: about 50G Built-in lithium battery capacity: 850 mAh Working temperature: (- 20 ~ +80 ) Storage temperature: (- 30 ~ + 85 ) Receiving frequency: 433.92MHz parameters: Working temperature: (- 40 ~ + 105 ) Storage temperature: (- 40 ~ + 120 ) Pressure range: 0 ~ 116psi (0 ~ 8bar) Pressure accuracy: 0.15PSI ( 0.01bar) Temperature accuracy: 3 Transmission frequency: 433.92MHz Battery life: about 2 years Size(approx.): Height: 13mm/0.51in, Diameter: 18mm/0.71in Weight: about 6.0g