[High-quality material] The use of high-quality Aluminum alloy, with high hardness, can cope with the needs of multi-directional drilling. [6 size drilling bit] M14 sleeve, 20mm, 35mm, 40mm, 45mm,50mm and 68mm. [Strong versatility] Suitable for all angle grinders with M14 sleeves [Punching range]: This drilling bits can meet the drilling needs of most people, and can be used on a of materials, such as , porcelain, granite, , plastic, glass fiber, , etc. It is commonly used in materials and stone. Casting, composite materials and other industries. [Precautions] use cold water for cooling after using the drilling bit, which can better the service life of the bit. Material:Aluminum alloy colour:black Package Contents: 1 * Diamond Core Bits Set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.