JawayTool 6pc Diamond Needle File Set Soft Grip Stone Tile Glass - Lifetime Warranty Heat-treated high diamond construction is work on all natural materials marble, wood, stone, bone etc. Excellent for stock removal in a variety of applications General purpose selection for home and professional use Handles features ergonomic shape co-molded material for better comfort and control Set of 6 files fits easily and securely into rugged, compact case