Grade R welding hose set, suitable for connecting acetylene torches with size B (⁹⁄₁₆" - 18) fittings. The interior diameter of the hosing is ¹⁄₄" and the length is 12 ¹⁄₂ feet. Hoses and fittings are color-coded for easy identification. Not suitable for use with LP, propane, or natural gas.