3.5" x 4" BHA Rubber Expanding Drum 3/4" Quad Keyway, use with Sanding Bands

3.5” x 4” x 3/4” quad key shaft Rubber Expanding Drums by Black Hawk Abrasives are designed to be used with BHA sanding bands. This design allows the drum to expand and hold the belt tight while in use but, when stopped the sanding band can be slipped off and replaced with another.