Supplied as a set of four drum sanders with interchangeable mandrels to suit your size of drill chuck. Replaceable abrasive sheets are quickly inserted and held in place with an alloy locking cam (additional strips of abrasive can be cut from whatever you have available). Sizes are 25mm(1"), 53mm(2.1/8"), 63.5mm(2.1/2") and 75mm(3") diameter, all 75mm high. Max speed 1500rpm.