This harness was designed for someone looking for a harness that is long enough to reach to the rear of your car or truck and power an RTL. The harness comes equipped with high quality sheathing and a relay to power all the functions; running light, brake, and cargo/reverse light. If you have purchased an RTL-S please purchase harness 64-0130. 64-0130 will include jumpers to tap into your turn signals.