The concrete hole has high hardness and great wear resistance which prevent from breaking and offer long term durability. Alloy , not prone to chipping off the edges, welding openings is very strong, precision engage, appearance is beautiful, practical in functions. Features -Color:Silver -Material:Alloy -Size:33.00X2.00X2.00cm,7.00X2.50X2.50cm/12.97X0.79X0.79in,2.75X0.98X0.98in -Made of alloy material, sturdy and durable, featuring impact resistances, stability and corrosion resistance. -This hole skit easily drills through most common wall materials, such as brick, concrete, cement, and -The hole are designed with sharpen teeth, the vibration is small, and the opening is more stable -Designed with external thread adapters to match your drill chuck, it greatly increase the drilling speeds. -The cement brick drill bit is suitable for cutting concrete, drilling walls, brick engineering, stone, etc. Package list: 1 x hole opener 1 x rod 1 x center drill 1 x screw