Premium Diamond Coated Tips - Features high-quality diamond particles for efficient grinding and drilling through beach sea glass, stone, rock, ceramic, and seashells. steel construction ensures long-lasting performance. 1/8"(3mm)shank compatible with rotary tool 1/8"(3.175mm) collect for drilling, engraving, and deburring in jewelry making, crafts, and DIY projects. Versatile, 1mm, 2mm, 3mm tip sizes - Perfect for detailed work on small stones, sea glass, and delicate materials. Great for enlarging holes or creating precise openings in beads and pendants. Water Cooling Recommended - Works best when used with water (submerged or with a drip) to prevent overheating and extend bit life. Avoid dry drilling for optimal results. 30-Piece Value Pack - Affordable bulk set with a storage case. Replace worn bits easily-ideal for hobbyists and professionals who need reliable, cost-effective grinding tools. Color: Silver Material: Specification: Package Contents: 30*pcs diamond drill bits Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.