The Rhino-Rack RL Leg Brackets are specially designed heavy duty legs to fit to gutter mounts on a vehicle. RL Legs come in a variety of shapes designed to fit specific vehicles. There are four main leg heights depending on how much clearance your roof racks need. RL legs come in 110mm, 150mm, 210m and 280mm heights. Rhino-Rack RL Legs are also compatible with Rhino-Rack Vortex Bars.