7 sizes: The drill bit set includes 7 different sizes: 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, and 12mm. These glass drill bits are suitable for various drilling tasks, offering high precision and can be used with electric drills. High-quality materials: Made with high-grade steel and cemented carbide, these drill bits feature high hardness and durability, improving work efficiency and maintaining a longer cutting edge life compared to standard steel bits. U-shaped groove and triangular handle: The spiral U-shaped groove ensures smooth chip removal for cleaner drilling. The triangular shank design provides a secure grip, preventing slippage during use. Spear tip design: Featuring a tungsten carbide tip, this drill bit is sharp and precise, allowing for easy positioning, stable drilling, fast performance, clean hole openings, and reduced risk of material cracking. Widely used: Suitable for drilling into ceramic tile, concrete, brick, wood, plastic, glass, and masonry. Ideal for home improvement, repair projects, and DIY applications.