size :
1/4" x 1-3/4"

application :
Grinding wheel with
up to 1/4" width.

size :
3/8" x 1-3/4"

application :
Grinding wheel with
up to 3/8" width.

size :
1/2" x 2"

application :
Grinding wheel with
up to 5/8" width.

size :
5/8" x 2"

application :
Large size wheel and centerless wheel.
(use on OD of tool)