This is a pediatric oxygen regulator for the use of regulating the pressure and flow of oxygen from an oxygen tank to an ozone generator. It features slow flow rates from 1/32 litre per minute in clickable stops to 4 lpm. This regulator fits most welding oxygen tanks in North America.
High quality brass and aluminum design.
CGA 540 screw-type fitting for use with welding oxygen tanks and some medical oxygen tanks with a valve like the one in the second picture.