The Makita 123221-8 Caulking Gun Piston C Complete is used to support smooth and controlled dispensing of sealants and adhesives from a compatible caulking gun. It works by applying pressure to the material cartridge, pushing the contents through the nozzle for consistent application. Replacing a worn or damaged piston can help restore proper dispensing function and maintain reliable ... https://www.wholetoolbox.com/makita-123221-8-caulking-gun-piston-c-complete/123221-8.html