Support Type:1. Works with all compatible vehicles obd-ii 2. Wireless (WiFi version) 10 ~ 20 m 3. iCar (WiFi version) support for software applications For iOS (iPhone4 / 4S / 5 / 5S / ipad / mini), (Android, java, etc.)
Working Principle: It is worn over the ear and has an electronic position sensor. When your head nods forward, it sounds a loud alarm to instantly wake you and alert your passengers.