Dive Kit

This is my right side, stage regulator (reg). A stage cylinder is an extra tank of gas, usually with a high oxygen content. Oxygen helps to flush out the nitrogen from your system, reducing the risk of DCI, and getting you out of the water a bit quicker than breathing good old air.

The big lump of shiny stainless steel is the first stage (not a cylinder in this case but stage one of the demand valve or regulator that lets you breathe underwater), it's job is to step down the pressure of gas coming out of the cylinder at about 232 bar (pretty high) to around 10 bar. The second stage (the black bit with a mouthpiece) steps the pressure down a second time, from 10 bar to ambient pressure so you can breathe easily.

Last time I used this reg there was a leak from the first stage, where the hose for the pressure gauge is attached. Nothing serious, just a bit of fizzing, but I thought I'd give it a good clean and see if that fixes it.