Bikegear Load Stops is a multi-position, t-track compatible stops help support and stabilize a wide variety of loads. Aero Load Stops are vertical rack attachments designed to stabilize and prevent side to side load shifting. Aero Load Stops are ideal for stabilizing light loads of lumber, ladders, pipe, canoes, etc. Aero Load Stops are designed to fit Thule AeroBlade, Rapid Aero, Xsporter Pro and Xsporter bars. Aero Load Stop set includes 4 load stops and all associated fastening hardware. Made of die-cast metal with a tough powder-coat baked-on finish and zinc-plated hardware, the load stops will provide many years of dependable, corrosion-free use. When used with Heavy-Duty Straps which are available separately, youinchll have an excellent solution that will give you confidence when transporting gear.