The standard spool has a flange in the center and is compatible with most SPG's, but a few SPGs, typically the plastic body ones, may only accept a spool without a shoulder in which case you will have to reuse the air spool from the SPG or order one specific to our gauge.

All high pressure SCUBA hoses use an air spool with two tiny o-rings to mate the swivel connector on the hose to the fitting on the gauge or transmitter. If the O-rings are worn or the spool is omitted entirely, the hose will have a small leak at the swivel. The air spool helps to form the seal between the SPG and HP hose and assists in controlling the pressure as it flows to the SPG from the first stage. Includes two oxygen compatible 003 O-rings