Flap discs with reinforced plastic backing and thread M14 with ventilation holes. Zirconium and corundum abrasive cloth admixture Bi-Lamellar with flat shaped back pads. Thanks to the wider flaps in superimposed pairs there is a guaranteed increasment of the abrasive surface while the union of zirconium and corundum increases the versatility. It does not overheat the material being used. The threads of the M14 pad allows direct mounting on the most common angle grinders of medium and high power without the use of a classical fixing nut. Ideal on stainless steel, high alloy steels and for cast Iron, alluminium and light alloys.