Abrasive refills for the Luna base, pack of 50. Available in grits 100 and 180. Black refills are moisture-resistant and silicone-backed, with a firm, non-shedding abrasive. Collect 90% of filing dust. Before use, smooth the edges with a buffer using downward strokes to remove the sharp edge left by laser cutting. Gray refills are not moisture-resistant, with a soft, velvety silicon carbide abrasive and no silicone coating. Greece.