Sanding Block Swop Block Sheet Extra Extra Coarse - approx. UK 80 tungsten carbide grit. The interchangeable Steel sheet folds around the end of the block, the punched holes enable a quick release and secure fit. SHEET Size 170 x 70mm. Block size when the sheet is fitted 120 x 70mm. A very popular roughing out block, popular with Stone Masons. The same as Cintride sheets. FINE approx. equivalent UK 420 / US 130 grit sandpaper MEDIUM approx equivalent UK 220 grit anadpaper COARSE approx. equivalent UK 180 grit sandpaper EXTRA COARSE approx. equivalent UK 120 grit sandpaper EXTRA, EXTRA COARSE approx equivalent UK 80 / US 24