This is an excellent compromise for the angler that is looking for an inexpensive but reliable regulator. 11 Settings: OFF, 1/32, 1/16, ?, 1/4, ½, ¾, 1, 1½, 2, and 4 liters per minute. These settings will allow various oxygen ratios with inexpensive air stones. The KA903 also provides sufficient pressure and oxygen for premium quality diffusers such as KA970-O2, KA975 and KA9100 diffuser. Gold aluminum body with brass components. Designed for use in a marine environment. EXTRA protection to prevent moisture and dust contamination. The extension next to the hose barb keeps contamination from entering the orifice required for all regulators. The red dust cap provides additional protection if left on. 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.