Diamond Drill Bits Set, 5 Piece Dry Diamond Hole Saw With Quick Change Hex Shank Product Details Specifications: The diamond drill bit set contains 4 pieces of dry diamond bits of different sizes, including Diameter 1/4 inch(6mm), 5/16inch (8mm), 3/8inch (10mm) 1/2 inch (12mm); Connection: 1/4"; Diamond height 10MM Vacuum Brazed Diamond Technology: diamond drill bits are crafted with carbide and top-grade diamond, suitable for tiles, porcelain ground, granite ceramic glass mirror marble stone masonry brick and so on; Note: not applicable to wood. Dry Drilling Design: The diamond drill bit is integrated with cooling wax. The wax melts while drilling absorbing and dissipating heat allowing for Dry drilling (water may be added for longer life and harder stones). 1/4 inch Hex Shank: The tile drill bit set is equipped with a 1/4" hexagonal shank. Quick change hex shank provides a better chuck grip and fits, which is compatible with most machines. Easy to carry and use: This Diamond Drill Bits set comes with a portable storage case for convenient use and store. If you encounter any problems in using the products, please feel free to contact us for satisfactory customer service. Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.