I.Trailer wiring harness kit is made of 18 AWG pure copper wire，our plugs are equipped with waterproof and dustproof protective covers to ensure reliable and durable performance in various weather conditions. The outermost layer is reinforced with black woven nylon mesh, which is durable and well insulated. The outer layer is made of thick PVC wire coating material to ensure your safety.  II. 4 Pin 5 Wire Trailer Wiring Harness kit has 5 wires It can save the trouble of additional wiring by providing enough wires to connect all necessary points without the need for extension or complex splicing.  trailer wiring kit fits trailers up to 80 inches and over 80 inches in width  III. 4-pin trailer harness adapter adopts a Y-shaped design, which does not require wiring on the axle like most other vehicles, and can be separated from different sides of the trailer.  IV.2.5-foot ground wire has a total length of 22 feet and provides sufficient length for flexible installation and trailer rewiring. The 5-wire trailer line is suitable for ships, trailers, and other trailers with 4-way plugs such as horse trailers, ATVs, and horse trailers