Black: external sensor black Silver: External sensor Silver Gray: Internal sensor gray Description: This is the newly developed TPMS Monitor Alarm system which works through Bluetooth 4.0 (Bluetooth Low Energy Consumption). Real-time tire detection to ensure traffic safety. Supports Platform: Android(Android4.3 and above bluetooth 4.0) Language:English You just need to install 4 TPMS sensors on Tires and they will send the temperature and pressure signal to mobile phone through bluetooth. You can view rea-ltime temperature and pressure through the APP you installed on Andriod device. APP will alarm when temperature and pressure of tires are abnormal. Please note: It only supports android Smart phone ONLY !!! It does not support car's navigation android system and no supports car DVD android system. Please first install the sensors and then connect to your phone.Otherwise it will connect failed and shows errors. Installation Steps: 1. Install the sensors to your tires 2. Connect the sensors to your Phone's APP. 3. After you installed and bound the sensors well, please open the app, please inflate or aerate the tire to activate the bluetooth of the sensors at the same time Sensor 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 Package included: 2 * sensor 1 * user's manual 1 * Bluetooth Moudle