Stainless steel compression fitting union straight is made of 316 stainless steel for resistance to scaling and corrosion, connects inline two tubes with equal diameter on both ends. Stainless steel compression fitting has a double ferrule construction to reduce the possibility of leakage. Stainless steel compression fitting is suitable for use in high-pressure applications. Stainless steel compression tube fitting are compatible with stainless steel, carbon steel, copper, rigid and semi-rigid plastic tube. Accommodate metric tube O.D ranging from 4 mm to 16 mm and inch (imperial) tube O.D from 1/8" to 1/2".