40 PSI Safety Valve for the following Newer Style MIDMARK-RITTER Autoclaves:
M9 020 thru 022 with S/N # V721881 thru present.
M9D 020 thru 022 with S/N # V721881 thru present.
M11 020 thru 022 with S/N # V721881 thru present.
M11D 020 thru 022 with S/N # V721881 thru present