For rotating pistons back into the caliper to provide clearance for new pads. Includes 5 adapters (available individually) for use in both 2 and 4-wheel rear disc brake assemblies of most domestic and import cars. Tool may be used "on" or "off" the car. A real time saver that makes this tough job easy. Helps prevent damage to the piston and boot. Shipping wt. 4 lb. 8 oz.