ZCI(TM) Zero Contact Interface Universal ModuLiteA(R) & Installation KitZCI 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 wiringIsolates 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.