Diode Hy-Power 4/pk.

By preventing electrical feedback, HY-POWER diodes allow you to splice into the towed car's wiring system without damaging expensive electronic dash components. Reduces wiring hassles for trouble-free operation for all vehicles. Heat sink dissipates heat and a heavy-duty 85 amp rating. 35° temperature tolerance. Simplifies wiring comes in a two pack required for most vehicles.