The product has never been used, the packaging was damaged during transport. Unopened product, repacked in our warehouses, in perfect working condition, warranty available. 【Multiple Diameters】In addition to the 5, 6, 8, 10, and 12 mm tile drill bits, you also get a 6 mm carbide drill bit. This saves you from having to drill with a diamond drill bit and allows you to drill holes even more precisely and easily. 【Unique Dry Drilling Design】Internal wax provides cooling. Our diamond-tipped drill bits have built-in wax cores that automatically absorb and dissipate heat during operation. Dry drilling produces no water and reduces environmental pollution. 【Multiple Uses】Porcelain tile drill bits, perfect for drilling clean holes in hard materials such as tiles, porcelain, granite, ceramics, glass, mirrors, stone, and brick. Note: Not suitable for wood, metal, or plastic. 【Compatible Round Shank】The glass drill bits have a round shank and are compatible with most machines, such as hand drills, angle grinders, and bench drills. The side grooves help clear debris and drill holes easily and quickly. The depth marking is also useful for some projects. 【High-Quality Materials】The drill body features vacuum-brazed diamond technology for extremely high efficiency, faster cutting, and longer lifespan. 6-piece diamond dry drill bit set: 5, 6, 8, 10, 12 mm and 6 mm carbide drill bits. Ideal for drilling clean holes in hard materials. High-quality and high-temperature resistant diamond grit for efficient drilling. Filled with cooling wax, suitable for dry drilling. No cooling is required during drilling as the drill bits are equipped with cooling wax inside. However, this can extend the life of the drill bits. How to use it? 1. Install the rotary hammer drill on the hand drill for use. 2. The electric drill maintains a high speed and tilts at 45° throughout the process to obtain the crescent groove. 3. After drilling the positioning groove, place the electric drill vertically, shake it slowly in one direction, and drill. 4. Drilling is complete. It is important to use a slight rotating motion when drilling! This ensures optimal drilling results. Note Forbidden materials: cement, metal, tempered glass, wood, plastic, etc. When using a cordless screwdriver, make sure the speed is above 1600 rpm. When using a hand drill, make sure the speed is above 2000-3000 rpm. 5/6/8/10/12 mm dry diamond drill bit set 6 mm carbide drill bit Drilling depth: ≤ 35 mm Length: 65 mm