30" Stainless Steel Straight Mud Flap Hanger 1 1/8" Semi Truck Tapered VolvoMud flap hangers are used on semi trucks and trailers in order to hold up the mud flaps over the tires that keep the trucks frame clean and clear of salt and debris on the road. Mud flap hangers are also necessary as they provide safety for others on the road. Not only do they keep your truck safe from rust that can come with a lack of protection, but they also keep those on the road out of harms way by stopping rocks, gravel, and other things flung