Style:  Type 21E inch/imperial series
Dimensions: 
Shaft:  5/8" (15.9 mm)
Seat Bore:  31.8 mm
Seat Thickness:  10.3 mm
Working Length:  22.2 mm (As measured from the rotating face to the back of the spring, under normal compression.)
Materials: 
Rubber Parts:  NBR Rubber
Faces: Standard Ceramic