STANLEY Mouse detail sanding sheet fingers are fully compatible with the BLACK+DECKER Mouse sander. The STA32477-XJ contains 15 x sanding sheets in a range of grit sizes (120G, 180G, 240G). The grit size refers to the size of the particles of abrasive materials embedded in the sandpaper. 120G is considered to be a fine grit level, Suitable for the sanding of bare wood in preparation for finishing or cleaning plaster and water stain from wood. 180G is considered to be a very-fine grit level, Suitable for the careful sanding of bare wood, whilst 240G is finer still, suitable for sanding wood between paint coats.