Century drill 77112 – drum sander 4pc kit -1/4″ shank – 1-1/2 x 1-1/2″ drum sander kits. Aluminum oxide grit, bonded to a cloth back. Ideal for sanding wood, fiberglass and metal surfaces and edges. 1/4″ shank fits all types of electric and cordless drill. 4pc kits include one drum with one coarse, medium and fine abrasive sleeve.