United Abrasives- SAIT 73688 4-1/2-Inch 80 Grit Zirconium United Abrasives- SAITlam UK Fiberglass Backing Sanding Disc, 10-Pack Fiberglass Backing - Saitlam UK - Conical shape ideal for working with large surfaces or complex shapes. Working angle is "built-in". For general purpose stock removal and finishing.