One thing to be aware of is that they originate in the USA so they are 1/4 NPT not BSP. What I did with mine is put a 1/4 NPT hose barb in then a length of soft rubber air hose with a ball valve in and an airline fitting. That way I can turn the air off with unplugging.
They are really useful for other things too, you can change PAS fluid in no time, suck the reservoir dry, fill with fresh,run and do the same again. If you are doing a brake fluid change you can suck the reservoir out and fill with fresh so you have a clean starting point. Oil change on a lawn mower is a breeze, no messing about tipping it on it's side.