Yakima Showboat Kayak Rack Rooftop assist roller that makes it easy to load boats onto a rooftop carrier Ensures that you'll never have to lift more than half of your boat's weight Accommodates BigStack, Mako Aero Saddles, Kayak Stacker, and other carriers Slides out to protect vehicle and slides side to side to protect your back Built-in locking system; stainless-steel and brass hardware; lifetime warranty