Package Include-----5pcs 1- 3/16 Inch(30mm) mini blades; 1pc 1/4 Inch(6mm) round shank; 1pc screwdriver; diameter 30mm; diamond height 7mm; thickness 1mm; diamond grit #100/120 Application-----Used for glass, jade, crystal, ceramic tile, marble, soft artificial stone and other materials cutting and engraving work. Wet and dry use, add water to use, the service life is longer High Quality Material-----Selection of high-grade quality diamond raw materials, vacuum brazing technology processing, long life, more durable, cost-effective Ultra-thin Blade Design-----Cutting glass, jade, crystal, tile, marble and other materials, will not cause damage to the surface of the object broken, cutting small and smooth, is a professional and DIY craft enthusiasts must-have tool Recommended Machine-----Handheld Grinder (Engraving Machine), Hand Drill. Use electric hand drill: Recommended speed not less than 16000RPM; Faster the RPM, longer the drill bit's working life