Don't blow out fuses or damage your wiring. Modulites draw power directly from your vehicle�s battery to easily turn your trailer light functions on and off. Converts your vehicle from a 3-wire system to a 2-wire trailer system. Heavy duty Modulite is rated for up to 4.2 amps for turns/stops circuits and 7.5 amps for the taillight circuit. Features an integrated re-settable short circuit and overload protection to safeguard itself and the tow vehicle from shorts and installation wiring mishaps. Works with either LED or Incandescent bulbs giving trailer lights full brightness. Designed not to send feedback thru the vehicle circuits. Interprets/decodes multiplex signal inputs (BMW & Mercedes applications).