Grade R Twin Line Welding Hose, 3 16 in x 50 ft, BB Fittings, Acetylene and Oxygen ORS NASCO and brazing applications Ensures pressure tight connections and brazing applications Ensures pressure tight connections made in seconds Built in automatic reset check valves prevent reverse flow of gas by cutting off the gas under back pressure Oxygen and fuel gas models are not interchangeable in order to prevent wrong connections Color coded for fast 21 inch glove with heavy duty padding on the forearm and elbow for comfort Super supple Genuine American Deerskin tanned in USA Genuine leather heat shield patch High quality Grade R twin line welding hoses Green hose carries oxygen to welding equipment Red hose carries acetylene Hose cover resists oils