The KeepAlive O2GO is the answer for a quality oxygen regulator with a price for all anglers. Rugged body components of brass, and nickel plated brass to withstand the rigors and harshness of the marine environment. 11 Settings: OFF, 1/32, 1/16, 1/8, 1/4, 1/2, 3/4, 1, 1-1/2, 2, and 4 liters per minute. These settings will allow various oxygen ratios with inexpensive air stones. Nickel Plated Brass with special internal components. Nut and Nipple style regulator body for use with CGA 540 Inlet Valve Cylinders. Oxygen tank pressure gauge with gauge protector. Barbed Outlet for direct attachment of oxygen tubing.