Heleta's Flap Discs have no equal. The time and money saved allows you to get the job done sooner and more economically. Three times faster material removal than fiber resin metal sanding discs, our Flap Discs grind and finish at the same time. The overlapping abrasive cloth also provides up to twenty times longer life, and allows for aggressive edge grinding. Lightweight fiberglass backing provides optimal grinding angle of either a Type 29 (10 to 25 degrees), or a flat Type 27. Aluminum oxide discs allow affordable grinding and finishing of wood, plastic, and most metals, except stainless steel and aluminum which require zirconia.