Dorma's 8900 series, grade one hydraulic surface closures are housed in a corrosion - resistant aluminum with a hardened piston/pinion providing toughness and high strength. The arm hub is made of forge deal. Heavy duty parallel arm with Spring Door Saver. This item is in the category "Business & Industrial\Building Materials & Supplies\Commercial Doors & Door Hardware\Commercial Door Hardware". The seller is "mary5432013" and is located in this country: US.This item can be shipped to United States.