Griton industries manufactured over all economy in all purpose flap discs. Flap discs are made from premium aluminum oxide or zirconium grain, bonded on phenolic backing. Available in various sizes from 4" to 7" in type 27.  Designed with high resistant to heat and moisture which is an ideal for heavy duty sanding.  Fit  most right angle grinders. They are generally suitable for ferrous and non-ferrous metal, best use in application such as rust removal, surface preparation, deburring, and weld seam blending.