Pop one of these into your 1st Stage HP Outlet then attach your HP Hose to the adapter and you'll have a HP Hose Connection that will swivel 360 decrees. Significantly reduces stress on the hose. Greatly assists superb, tidy hose routing. Helps you to position your gauges for easier reading. Your HP Hose will be able to rotate a full 360 decrees, just like a windmill. Standard 7/16th Fitting so will fit 99.9% of Regulator 1st Stages.