Check the listing for details. OEM Tools 25071 Rear Disc Brake Piston Tool Rear Brake Caliper Compression Tool. Condition: Used, Made in United States. Listed at 13.99 USD. This is an OEMTOOLS 25071 rear disc brake piston tool. This cube-shaped tool rotates brake pistons back into the caliper, which is necessary when replacing worn-out brake pads. It is designed with five different drive pin configurations on its faces to fit most vehicle applications. The tool is operated using a 3/8" square drive socket wrench or extension. It is explicitly labeled "NOT FOR IMPACT USE," as impact wrenches can damage the tool or the brake components.