Description:The high adaptability makes it very suitable for different electric drills. And the hexagonal shank makes it very firm and stable.Anti-rust and durable features make it can be used for a long time. High quality and professional workmanship make it have high hardness.Made of hard alloy material, it is very durable to use.There are seven specifications for you to choose from: 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm.It is a professional glass and tile drill bit that can provide accurate drilling on tiles, marble, thin iron plates, mirrors and glass. Remember to add water or coolant when drilling.Item Name: Lengthened Drill BitMaterial: Hard AlloyColor: BlackShank: Hexagonal ShankFeatures: Multifunctional, Anti-rust, Low Resistance1: 5mm, 6mm, 8mm, 10mm, 12mm, 2: 6mm, 6mm, 8mm, 10mm, 12mm, 3: 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 4: 5mm, 6mm, 6mm, 8mm, 10mm, 12mmSize Details: 3mm: Total Length: 9.8cm/3.86", Drill Bit: 0.3cm/0.12", Work Length: 4.2cm/1.6" (Approx.)4mm: Total Length: 9.8cm/3.86", Drill Bit: 0.5cm/0.2", Work Length: 4.2cm/1.6" (Approx.)5mm: Total Length: 9.8cm/3.86", Drill Bit: 0.5cm/0.2", Work Length: 5.5cm/2.17" (Approx.)6mm: Total Length: 10cm/3.94", Drill Bit: 0.6cm/0.24", Work Length: 5.5cm/2.17" (Approx.)8mm: Total Length: 11.7cm/4.61", Drill Bit: 0.8cm/0.31", Work Length: 5.5cm/2.17" (Approx.)10mm: Total Length: 11.8cm/4.65", Drill Bit: 1cm/0.39", Work Length: 7.5cm/2.95" (Approx.)12mm: Total Length: 12cm/4.72", Drill Bit: 1.2cm/0.47", Work Length: 7.5cm/2.95" (Approx.)Shank Diameter: 0.635cm/0.25" (Approx.)Notes:Due to the light and screen setting difference, the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1: 5 x Lengthened Drill Bits (5mm, 6mm, 8mm, 10mm, 12mm)or2: 5 x Lengthened Drill Bits (6mm, 6mm, 8mm, 10mm, 12mm)or3: 6 x Lengthened Drill Bits (4mm, 5mm, 6mm, 8mm, 10mm, 12mm)or4: 6 x Lengthened Drill Bits (5mm, 6mm, 6mm, 8mm, 10mm, 12mm)