This is the small oxygen regulator that fits disposable oxygen bottles (example Bernzomatic type bottles). No gauges, just a knob on top that adjusts pressure. The output is a 1/4" barb. The regulator is left hand thread. If you are tring to make a oxygenation system we sell the needed filter and aeration stone needed to complete the system. Also don't forget to check out out other great home brewing supplies and equipment. We also sell Brewery accessories like hats, shirts, tap handle, etc. Just click on the link below to enter our eBay store.