Don't let a loose Hose-Fitting or Valve Hand Wheel Blow an O-Ring or not allow Proper Valve Function Ruin a Dive. Not have the Proper Tools and Parts to Fix Problems can do just that! The Serious Diver is always prepared to Nip a Dive Aborting Problem. That's just two scenarios that this Star Tool can remedy. You ever see Non-Stainless Steel Tools when they have been Exposed-to-Salt Water Environments? Not a pretty sight. It also looks bad when you pull out your rusted open-end steel 9/16 x 11/16" to remove or replace a Standard 9/16" or High-Flow 11/16" Second-Stage Hose. Many of the new Low-Profile designed Hose Fittings may not even allow you to use a Standard Wrench.