Type MFR
The 16 ga. 304 SS flange is used as a means of securing the cartridge heater in place.
Type IS: Incoloy Sheath
The standard sheath material for all Hi-Density Cartridge Heaters except 1″ diameter is 321 stainless steel; standard for 1″ diameter is 304 stainless steel. The incoloy sheath option is available on all diameters except 1/8″, 5/16″, 8 mm and 20 mm.