United Abrasives- SAIT 73220 4-Inch by 5/8-Inch United Abrasives- SAITlam Flap Disc, 120 Grit, 10-Pack Excellent for miter joints, corners and edges 2A General purpose aluminum oxide Provides an even "finish ready" surface Nylon 6/6 backing a non-scratching, high strength backing resistant to temperature extremes, common chemicals and solvents