the matheson 3810 is a 100psi regulator. it came with a 200psi gauge.
the 3816 has a 400psi gauge.
(google matheson 3810 and look for the pdf)
Well I have already checked out the pdf info and supposedly the one I am to receive is a 3818 which came with a 0-400 gauge. That is because off the top of my head I think the operating pressure is from 15-350 or so. However the serial code only states 3810, I can't tell if thats a part of the series of 3810 or if its for the individual model. That being said it might be wise to get a smaller range so it will be easier to measure pressure. I was either thinking getting a 0-200 for nearly all applications (other than this hobby alone) or a 0-100 because it is easier to obtain. I would appreciate some help on the post body setup and would like to do all stainless but may have to wait a little while before I can purchase.