Larry, wow, thanks for the link That is the company for sure but the handles on the listed blasters are different than mine. Maybe they changed them in the last 15 years. As far as pressure goes, my gauge broke years ago when I accidentally sand blasted it while trying to build up pressure. So are you ready for a laugh - I close the main valve on the out put of the air compressor and open it the width of a 7/32nd drill bit. Yes, I stick the drill bit in there for the right measurement. Now, when I blast sheet metal - quarters - I also turn down the inlet to the sand blaster to 1/2 open. Not very scientific I know, but it has worked for me that way for years.

EDIT: I use an Ingersoll Rand compressor that holds up to 120psi on a 60gal tank, but I use much less pressure when blasting.