Mirro Pressure Cooker Model “646M or M-0646”. Parts List for Mirro Matic “646M or M 0646” Pressure Cooker. Mirro® parts for the Mirro® model “646M or M-0646” may be ordered on-line using the links below. Mirro 9898 Pressure Regulator 9898$17.95 Mirro 9894 Vent Tube 9894$9.95 Mirro 9892 Gasket 9892$11.89 Mirro 9732 Fuse Over Pressure Plug 9732Regular price: $2.99Sale price: $2.00 6 3/4 in. dia Canning Rack 341$7.49 8 in. dia. Canning Rack 360$8.95