3M radial plastic abrasive discs with embedded cubitron mineral. As the wheel wears, fresh abrasive is exposed. Discs are tough and long lasting.

Brush width can be adjusted for specific applications simply by adding or deleting discs. For example, use just a few discs on a 3M990 mandrel for thin spindle sanding or group up to 28 discs on a VLR991 mandrel for wide area coverage. 1/4" shank.