【9 PIECES CONCRETE DRILL BIT SET】: 5mm. 6mm. 6mm.8mm. 8mm.10mm.12mm.14mm.16mm * 160mm; The drilling depth is 100mm. With this, you can drill all common dowel holes. (For your machine and personal safety, it is not recommended to use a three-claw impact drill) 【X-SHAPED HEAD】 It features an X-shaped geometry with a cross-fluted design for optimal disassembly and ease of use. Fully hardened drill bit with a double flute spiral for efficient waste removal. 【2-HOLE SHANK】 Round handle double-slot hammer drill bit Regular drilling tools for concrete, granite, stone. It provides optimal dust and debris removal thanks to a rounded spiral geometry, more efficiently. 【CARBIDE DRILL BITS】 The drill bit set is made of high-quality carbide steel, durable and rust-proof. The tungsten carbide-tipped drill head is harder, stronger and more resistant to extreme loads. 【APPLICATION】 Suitable for drilling holes in concrete, ceramic tiles, stone, wood, aluminum, plastic, concrete and multi-layer