Zip Wheels are ideal for quickly and efficiently removing rust, paint, underseal, stone chip and sealant in preparation for welding, refinishing and other work, without attacking the steel. Purple Zip Wheel is used with your electric drill. Strips right into corners, grooves and mouldings without clogging. Ideal for removing door skins and preparing for welding work. The bevel shaped brushes are better for irregular surfaces, along edges and the cup shaped brushes are for larger flat surfaces.