The Unit Tool is a multi-functional skateboard tool that allows you to adjust the axle nuts (holds the wheels on), mounting hardware(holds the trucks on), and the kingpin nut (makes the trucks looser or tighter) on the top of the truck. It includes 3 sizes of sockets and a slide-out Phillips and Allen head screwdriver. It's slim size make it perfect for a backpack and is a tool no skater should be without.