This tire pressure monitor can display the four tire pressure in real-time, help users monitor the tire condition in-time, enhance riding safety, and has the function of clock,which is suitable for a variety of models. Features: Intelligent accuracy: real-time monitoring of four tire pressure, tire temperature, precisions and efficiency, can timely grasp the tire situation, reduce the incidence of accidents, and enhance driving safety. Two kinds of sensors are available: users can choose the built-in sensors set or the external sensors set according to their needs. Clock and power display: with clock display, it can display time, power and other information at the same times to remind users to charges in-time. Wireless transmission: data wireless transmission, intelligent and efficient, real-time update. Solar powered design: energy saving and efficient, in the process of driving can also charges, long lifes, but also can use USB chargings cable. 360 ° rotatable: the tire pressure monitor can rotate 360 ° and adjust 45 ° up and down, fixed at an appropriate angle and field of views. Specifications: Material: aluminum alloy + copper + plastics Type: Internal sensors set, External sensors set (optional) Receiver: Battery: built in 3.7V, 400mAh lithium battery Working voltage: Direct Current 5V Transmission frequency: 433.92MHz Pressure unit: psi / bar Temperature unit: Deg.C / Deg.F. Working temperature: -20 ~ 85 Storage temperature: -40 ~ 125 Internal sensors: Working pressure: 0 ~ 51psi / 0 ~ 3.5bar Pressure accuracy: ±0.1bar Transmission frequency: 433.92MHz Working temperature: -20 ~ 85 Storage temperature: -40 ~ 125 Working voltage: 2.0 ~ 3.6V Waterproof grade: IP67 Battery: built in CR24500 battery Battery lifes: about 2 ~ 5 years (not replaceable, the sensors needs to be replaced when the battery has run out of power) External sensors: Working pressure: 0 ~ 51 psi / 0 ~ 3.5 bar Pressure accuracy: ±0.1bar Working frequency: 433.92MHz Working voltage: 2.0 ~ 3.6V Waterproof: IP67 Working temperature: -40 ~ 85 Storage temperature: -40 ~ 125 Battery: built in CR1632 120mAh battery Battery life: about 1~2 years (replaceable battery) Item weight: Internal sensors set: 270g / 9.5ounce External sensors set: 170g / 6.0ounce Package size: 160 * 140 * 58mm / 6.3 * 5.5 * 2.3in Package weight: Internal sensors set: 320g / 11.3ounce External sensors set: 220g / 7.8ounce Packing List: Internal Sensors Set: 1 * Receiver 4 * Internal Sensors 1 * USB Cable 1 * User Manual External Sensors Set: 1 * Receiver 4 * External Sensors 4 * Screw 1 * Spanner 1 * USB Cable 1 * User Manual