The pressure regulator fits onto the vent pipe to indicate when 15 pounds pressure is reached, and controls pressure in the unit. A gentle rocking motion of the pressure regulator indicates that proper cooking pressure is being maintained. This also replaces Part No. 09913. Pressure indicator & regulator, for all pressure cookers manufactured after 1957 except 01/pa4, 01/pa6, 01/pa4h, 01/pa6h, 01/pa6hb, 01/pe3, 01/pe6, 0121001, 0125001, 0122101, 0126101, 0211101, 0115101, a617a.