Retail 4PCS Electrical Tools Diamond Drill Bit 1/4, 5/16, 3/8, 1/2 Inch Hexagonal Shank Vaccum Brazed Dry Drill Core Bits Wide range of usages:12 mm Diamond drill set fits well for drilling clean holes to hard materials, especially for tiles, porcelain ground, granite ceramic glass mirror marble stone masonry brick (not for wood). Gifts for men:This round shank diamond drill bit set is the nice gift choice for dads, male friends and husbands on birthdays or other holidays. Hurry up and add it in your gift list. Specifications:Colour:blackMaterial:DiamondPackage Contents:2 * Bits diameter of 1/4 inch(6 mm)1 * Bit diameter of 3/8 inch (8 mm)1 * Bit diameter of 5/16 inch (10 mm)1 * Bit diameter of 1/2 inch (12 mm)Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.