AirForce Airguns Swingline 2 fill system K-valve (fits a scuba tank) Built-in manometer (air pressure gauge) Max 4500 psi / 310 BAR pressure Hose ends with a female quick-disconnect fitting Push button air release (bleed valve) Independently position the valve clamp, pressure gauge and fill line and make it easy to fill your gun regardless of the position of the scuba tank. After filling, the hose can be rotated close to the scuba tank for convenient storage or transport.