1/2 NPT preferably 3/4, 0-140 PSI, Relieving, with built in filter, as long as it's not Ingersoll Rand. I already have a 2 year old $100.00 boat anchor. In my 51 years I have never had a regulator actually go bad like this, including at my uncles body shop when I was a kid. Made in Korea IIRC. This one acts like the relief valve is stuck open, if I diss-assemble then re-assemble its OK for a week, then sticks again. There seems to be some kind of chicanery with getting parts for this thing. I think it will make a fine target.