For disc brake caliper piston adjustment. Dual-purpose tool is used both to adjust the piston position by screwing it into or out of the cylinder bore and to push piston straight back in the cylinder bore. Kit contains center screw and T handle, plate, disc and adapters to work with all calipers, including rear calipers on vehicles with self-adjusting parking brakes. Any automotive specialty tool will help make an automotive repair or maintenance task easier, but Powerbuilt products take the concept of help a big step further. Every Powerbuilt specialty tool comes with professionally written usage instructions that take you step-by-step through proper tool usage. Photographs of the tool in use accompany the instructions. All developed by an automotive professional who writes and edits automotive service manuals.