Mounts on hard rubber drum.  1-1/2" diameter           5-5/8" long rubber drum.
Fits Powermatic machine as well as any 1.5" diameter x 5.625" long rubber drum.
Typical application is for woodworking.
Can be used on metal and plastics.
This item has a firm backing to maintain the round shape. 
Note: The photo shows the type of product that this is, but may not correctly reflect the size and grit of this item.  The size and grit is show above.