Usage Tips:1. Digital Display: Display speed, water temperature, instantaneous fuel consumption, hour fuel consumption 2. Performance Testing: Vehicle acceleration test 3. OBD2 Engine Diagnostic Functions: Data flow function display, display color configuration, fault code scanning, fault code clearance and other functions 4. Early warning function: Water temperature warning, over speed warning, shift warning. Specifications: Operating voltage: 9-18V DC Operating current: less than 80mA Sleep current: less than 10mA Operating temperature: -20~85℃ Product volume: 75mm x 55mm x 20mm Speed meter indication error Speed Meter indicates speed and actual speed according to formula : O less than or equal to Vn-VZ less than or equal to (V: + 10) + 4 V1- speed meter indicates speed in km/h V2- an actual speed in kilometers per hour (km/h). The vehicle speed correction is based on 100km/h. The error of the vehicle in the low speed state is the reason why the vehicle meter is not linearly displayed. Specifically, you can connect to the OBD socket test with a dedicated inst ent in the 4s shop. colour: black Material: ABS Package Contents: 1 x host 1 x OBD cable 1 x Chinese and English manual Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.