These heavy-duty, lightweight fire hose couplings are made from 6061-T6 high-strength aluminum alloy. Swivels are attached with a piston ring, stainless balls, or roller bearings. No roll-over or still threads are ever used to attach swivels. The 6061-T6 aircraft aluminum alloy gets a smooth hard-coat finish. Comes complete with rings and gaskets. All gaskets are lathe cut and the expansion rings provided are 85-15 red brass.