Wirthco 4-way trailer ends feature a Wishbone design and the standard rvi color code. Wirthco engineering is entering our fourth decade as a prime manufacturer of practical products for making life easier and safer - at home, in the workplace, on the road, in the campground and on the water. We are grateful for valued employees and customers and We are dedicated to continuing growth based upon integrity and service. We are also proud of our heritage of providing innovative quality products.