OBD Innovations0174; Mini ELM327 Bluetooth OBD2 Auto Car Diagnostics Scanner with Power Switch for Android ON/OFF Power Switch that allows you to keep it plugged in at all times Diagnose engine codes and clear check engine lights Connect to an Android Smartphone using one of the many available apps Data Logging: View real-time vehicle data while driving Find and fix problems before they happen; Pays for itself with one use