The package contains only one 16*160mm [x-shaped head]: it has an innovative x-shaped geometry with a unique cross-slot design for optimal disassembly and ease of installation. 'use. Fully hardened drill bit with double groove helix for efficient waste handling. [2 holes]: round handle, double hole drill bit, conventional drill bit in one red box for Concrete, Granite, Stone. It provides optimal removal of dust and debris more efficiently thanks to a circular spiral geometry. [specifications]: the size of the concrete drill is 16 x 160mm; Drilling depth of 100 mm. This way you can drill all common dowel holes. (For your machine and personal safety, the three-claw hammer drill is not recommended.) [Carbide Drill Bit]: The drill bit set is made of high carbide steel quality, durable and rust resistant. Tungsten carbide drills are harder, stronger and more resistant to extreme loads; High-density drilling and rapid waste disposal [application]: suitable for drilling holes in concrete, tiles, stone, wood, aluminum, plastic, concrete and materials multi-layered / suitable for all drill bits with SDS plus holder