ZCI(TM) Zero Contact Interface Universal ModuLiteA(R) - Universal Trailer Light Power ModuleZCI sensor technology and direct connection to the tow vehicle battery, eliminates all electrical connection and interference with the tow vehicle electrical system. Vehicles with 12 volt system only.Features:NO CUTTING OR SPLICING VEHICLE WIRING!Isolates Trailer Light Operation from Tow Vehicle's Electrical SystemWorks with 2 or 3 wire systemsWorks with PWM or Multiplexed systems requiring 2 or 3 wire hookupRated for up to 4.2 amps for turn/stop & 7.5 amps for taillight trailer circuitsWorks with low side switched vehiclesIntegrated auto resetting short & overload protectionRobust design allows for interior or exterior mountingWARNING: This product can expose you to chemicals including di(2-ethylhexyl)phthalate (dehp) which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.