AuInn Angle Grinder Grinding Discs, 4 1 2 Inch Flap Discs, 40 PCS 4.5" 4 1 2 Flap Disc 40 60 80 120 Grit Angle Grinder Sanding Grinding 25PCS Angle Gringer Cutting Disc 107mm 4 Inch Metal Cut Off Sanding 4 1 2" Flap Sanding Disc 40 60 80 120 Grit 4.5 Grinding Wheels for. About this item : Grit Material Aluminum Oxide Item Dimensions LxWxH 9. 45 x 8. 86 x 4. 72 inches Compatible Devices Angle Grinder Grit Number 120 Color redDescription: Size: Diameter is 4 1 2, Arbor is 7 8, the flap disc is standard size and suitable for most air and electric grinders. Specification: Type #27, the grinder sanding discs are better for smoothing and blending surfaces. Maximum speed 13300 revolutions per minute (RPM), the wheels perform well. Package contains: 40 60 80 120 grit angle grinder sanding discs, 10 x 40 grit, 5 x 60 grit, 3 x 80 grit, 2 x 120 grit, the combination better matches your requirement.