Century drill 77120 – drum sander 3pc refill -1/4″ shank – 3/4 x 1″ drum sander 3pc refill. 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 drills. 3pc refill includes one coarse, medium and fine abrasive sleeve.