Smooth outer surface prevents scratching and marring. Working pressure: 175 PSI. Manufactured of high impact composite material featuring nitrile seals. Stainless steel internal parts resists corrosion. Conforms to the ISO 4414 Standard for safetyAcme's new Composite Couplers are strong yet lightweight and manufactured of a heavy-duty, high-impact fiberglass composite to protect finished surfaces from the scratching and marring that can occur with brass or steel couplers. This Industrial Composite Coupler can be used with any standard Industrial Interchange connector. Also this has the 2 pawls locking device. It's easy push-to-connect allows for a quick connect, and the single release for an easy disconnection!