LP GAS, 1" FPT GAS IN/OUT, 1/2 PSI, 5.5"-12" WC, MAXITROL # RV53-88-0033 WITH VENT LIMITER #12A04, W-957, # 263305 MAINLY USED IN INDOOR APPLICATIONS TO LIMIT THE AMOUNT OF ESCAPED GAS IN THE EVENT OF A DIAPHRAM FAILUE. Bakers Pride M1067X Bakers Pride M1067X Bakers Pride M1067X