SMALL DRILL BIT SPECIFICATIONS: Each drill bit in this set measures 6mm (1/4") in diameter with a total length of 55mm (2"). The package includes 15 pieces, making it ideal for multiple projects around the home or professional use. HIGH-QUALITY MATERIALS: Constructed from industrial-grade carbon steel, these diamond ceramic hole saws boast a nickel-plated coating to enhance corrosion resistance. This durable construction ensures long-lasting performance and reliability. EFFICIENT DESIGN: Featuring large clearance holes along the drill bit, this design promotes the entry of cooling water and facilitates the removal of chips and other particles during the drilling process. This feature makes drilling smoother and extends the lifespan of the bits. VERSATILE APPLICATIONS: Perfectly suited for creating precise holes in a variety of materials including glass, ceramics, porcelain tiles, limestone, marble, light stone, and fiberglass. Ideal for both DIY enthusiasts and professional craftsmen. USAGE TIPS: For optimal results, start drilling at a 45-degree angle to the surface and gradually align to 90 degrees as the hole forms. Always use water to cool down the drill bit during operation to significantly extend its life. Color: As Shown Material: Metal Package Contents: 20*6mm Glass Hole Opener 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.