The Rhino-Rack Alloy Roller is a great way to get your ladders on and off your Rhino-Rack Heavy Duty roof racks with only a small amount of effort required. It is also a cost effective way of getting your ladder on your racks without a full ladder system. Simply attach the Alloy Roller to your bar and roll your ladder onto your racks. Made from a heavy duty alloy and supplied with a black plastic cover, the roller comes with a pair of roller bushes and brackets to attach to your Heavy Duty bar. The RR540 is a compact roller measuring at 540mm (21") in length.