The XS Scuba Brass 2nd Stage Quick Disconnect allows you to quickly connect or remove a second-stage regulator or full-face mask without using tools. Installed between the low-pressure regulator hose and the second stage, it simplifies equipment changes while helping prevent unnecessary wear on hose fittings. The durable chrome-plated brass construction provides long-lasting corrosion resistance, while the integrated lock-down screw helps prevent accidental disconnection during use. Designed for low-pressure applications only, the AC990 is an ideal upgrade for divers who regularly switch between multiple second stages or full-face masks.