E-Z Red MS4000 Automotive Memory Saver With Built In Charger Protects settings and codes for: Anti-theft radios Clocks Keyless entry systems Alarms Cellular phone settings GPS Memory TPMS Other memory related functions Saves all drive-ability codes and settings when disconnecting/changing a vehicles starter battery Direct wired OBDII Connector plug directly into the vehicles OBDII Port 12 volt, 4.5 amp hour sealed lead acid battery included inside unit Power on / power off switch Green LED indicates connection to circuit Amber LED indicates when the internal battery is 11.6 volts or lower and requires charging soon