【Package】Include 5pcs 6mm(1/4") Dry Diamond Drill Bits and 5pcs 6mm(1/4") Carbide Drill Bits. 【Size】Total length 65mm, diamond height 10mm, working depth 30mm, shank length 20mm, generally hand drill in 2000-5000RPM, the faster the better, the slower then the shorter life span. 【Machine】Compatible with most popular electric drills, angle grinders and bench drills, do not use impact or hammer mode. 【Widely Use】 Dry Diamond Core Bit set is able to drill all types of tiles, porcelain, granite, ceramic, glass, marble, stone, masonry brick. 【Good Performance】Triangle shank design for stable clamping, smooth and easy drilling, fast and smooth cutting, be more efficient and durable.