As our passion for cycling increases, so does our bike collection, so we pick up the Kuat Piston Pro X Hitch Rack Add-On when we need to haul three or four bikes along for the ride. This add-on quickly and easily transforms the two-bike Kuat PXA2G Piston Pro X 2 Bike Rack platform into an up to four-bike transporter. Loading the extra bikes into the rack is a breeze with no bike frame contact, a FastFit wheel chock system, and OneTap levers.