This aluminum, folding rack lets you safely transport 1 kayak on your vehicle's roof. Folding arms pivot to accommodate almost any size kayak or paddleboard. Universal clamp-on brackets mount on most roof rack crossbars with no tools required.Then slide the mounting clamps underneath your roof rack's crossbars and attach them to the cradles with the included hardware. Use the included hand knobs to easily tighten and secure the clamps around your crossbars.