Tuff Country 14-18 Silverado 15 4x4/2wd (Alum/Stmpd 2pc Stl Up Cntrl Arm) Uni-Ball Up Cntrl Arms PrTuff Country EZ Ride Suspension's uni ball upper control arms for lifted trucks will greatly reduce binding that can be caused by standard ball joints, while also providing additional suspension travel. A great addition to an existing 2 inch to 4 inch suspension lift kit (vehicle must be equipped with factory steering knuckles). Also available as an option in complete lift kits for some Tacoma, Tundra, F 150, Silverado 1500 and Ram 1500 models.