Park Tool PP-1 Hydraulic Brake Piston Press
The unique, wedge-shaped PP-1 slides into a hydraulic disc brake caliper to pre-set the piston when replacing pads, aligning pads, and performing other service procedures. The Park Tool PP-1 Hydraulic Brake Piston Press makes disc brake maintenance and repair faster and easier than ever before.
Another purpose made. I've used big screwdrivers as an alternative to this, and they always scuff up the pads. This tool does it right every time.