Splice into your tow car's wiring without damaging expensive electronic components. Diodes are used to tie into the towed vehicles brake light, running light and turn signal wiring, and connect it to the motorhome. Diodes permit electrical current to flow in only one direction from the motorhome to the towed vehicles taillights preventing electrical feedback and the damage it can cause to both vehicles electronics. If youre using a diode, why not use the best? Hy-Power diodes have a heavy-duty, powder-coated aluminum heat sink, and each diode is protected against the elements all components are housed inside an epoxy-sealed, powder-coated aluminum case. Includes detailed wiring instructions. | Roadmaster HY-Power Diodes - 2 Pack