Tilton main and intermediate pressure plates for 5 1/2'' (140mm) metallic clutches.
The main pressure plate is the plate which is ridged on one side where it contacts the diaphragm spring and flat on the other side where it contacts the driven plate.
There are a number of variations of this plate available.
The intermediate pressure plate or floater plate is the flat plate which sits between the driven plates on Tilton multi plate clutches. There are different plates depending on which Tilton 5 1/2" (140mm) metallic clutch you have.