Designed to remove and install frost plugs used in liquid-cooled gas and diesel engines found in automobiles, trucks, SUVs, agricultural equipment, and construction equipment Simply use a hammer with the driver and appropriate disc to install frost plugs ranging from 1 inch to 2-3/8 inches in diameter Set contains: OTC 4603-1 Installer Handle (18 inches long.); OTC 4604-2 Frost Plug Remover; OTC 4604-3 Frost Plug Disc Set (7 each plus 1 retaining nut)