Feature:* .* , and practical.* The carbide end mill has stronger hardness. Carbide drill bits are and can stay sharp longer than typical steel drill bits.* Precision drilling: The drill bit has a smooth hole, no edge, no shaking, easy positioning and better drilling speed.* The spiral torsion shaft increases the cutting area and leaves a clean hole. Combining chip removal and drill bit, the pointed design is more convenient to use, saves time, and can punch holes quickly.* The solid tungsten carbide tip with pointed design can easily penetrate a variety of materials (porcelain tiles, glass, mirrors, plastic bricks, and wood).* If you use the drill bit to drill concrete, brick walls, and other hard materials (glass, porcelain floor tiles, marble or granite), use water for lubrication.* There are 7 specifications for you to choose: 3mm,4mm,5mm,6mm,8mm,10mm,12mm. Specification:Material: Cemented CarbideColor: BlackSize:Head Diameter: 3mm, Handle Diameter: 2.4mm, Working Length: 58mm, Overall Length: 80mmHead Diameter: 4mm, Handle Diameter: 3.6mm, Working Length: 58mm, Overall Length: 80mmHead Diameter: 5mm, Handle Diameter: 4.5mm, Working Length: 58mm, Overall Length: 80mmHead Diameter: 6mm, Handle Diameter: 4.8mm, Working Length: 62mm, Overall Length: 100mmHead Diameter: 8mm, Handle Diameter: 6.4mm, Working Length: 68mm, Overall Length: 110mmHead Diameter: 10mm, Handle Diameter: 8.3mm, Working Length: 78mm, Overall Length: 120mmHead Diameter: 12mm, Handle Diameter: 8.3mm, Working Length: 75mm, Overall Length: 125mmPackage Included:5*Drill BitsPlease Note:-Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!-Manual measurement, please allow 1-3cm error. Thank you for your understanding.