The Abracs HCT1 5 Piece Kit consists of 4 Polydiscs 50mm diameter and an alloy power tool adapter with 1/2 inch drive. Ideal for removing rust from brake discs and hubs. The anti-clog construction keeps the abrsasive minerals cutting at a higher rate. The alloy adapter enables quick disc changes with the convenience of running on high powered tools. Can also be used on paint before preparation. The unique design of this product ensures a minimal risk of scratching the work piece during use. Ideal for use in hard to reach places. Abracs HCT2 Threaded Polydisc Replenishment Pack contains 10 spare Polydiscs.