Spiral-stitched construction with 40 layers of cotton. For pre-polishing, cutting and flattening. For best results use one compound per wheel. 16mm / 5/8″ bore for use with all 150mm bench grinders and polishers. Can be stacked onto tapered spindles to achieve required thickness. Spiral-stitched construction with 40 layers of cotton. For pre-polishing, cutting and flattening. For best results use one compound per wheel. 16mm / 5/8″ bore for use with all 150mm bench grinders and polishers. Can be stacked onto tapered spindles to achieve required thickness.