Item Type: Hole Opener Drill Bit_x000D_ Material: High speed steel_x000D_ Cutting Diameter: Approx. 19mm / 0.75in 1High Efficiency: Designed by the inner, middle and the outer 3 flutes, with high opening efficiency, and is not easy to collapse. 2High Speed ??Steel: Made of high speed steel material, with high strength and corrosion resistance, not easy to deform after long term use. 3Small Resistance: The saw blade has large gaps, which can reduce the resistance when opening a hole and quickly remove chips. 419mm Diameter: The cutting diameter of the hole opener is 19mm, the hole is round and has no gaps, with good smoothness. 5Wide Applications: Suitable for cutting and drilling of marble, ceramic tiles, walls and other stones, fast and labor saving. 1 x Hole Opener 1 x Hex Wrench 1 x Spring