Features:* Brand new and high quality.* It is made of high quality YG6X alloy as raw material. Oxynitriding process cutter head strengthen the hardness of the drill bit.* Full grinding and anti-corrosion treatment, clean and sharp without burr. The drill bit is more wear-resistant and durable.* Low cutting resistance, stable drilling, fast speed, no boundary breaking. Opening neat, smooth, no broken edges, no shaking phenomenon, easy chips.* Professional glass and tile drill bits ensure smooth and accurate drilling into ceramic tiles, marble, thin iron, mirrors and glass. Remember to add water or coolant when drilling.* 7 different sizes, suitable for different needs. Can be installed in general electric hand drill, bench drill. Specifications: * Material: Carbide * Color: As picture shown * Size: 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm * Quantity: 7pcs Package content: 7 * universal drilling tool Notes: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.2. Please allow slight manual measurement deviation for the data.