Wall hole opener, also called hollow electric hammer drill, welded with high quality alloy, used for opening holes in brick and concrete buildings, special for electric hammer, can hit brick wall box cement wall red brick wall, can't hit steel, tile and stone. Can play air conditioning holes, water pipe holes and range hood holes, etc. Anti-slip slot, clamping tight not to slip, drilling is not easy to deformation, durable.Size recommendation:Diameter 30: 4 points pipe (general water pipe and water heater pipe)Diameter 35: 6-points pipe (general tap water pipe and water heater pipe)Diameter 40: 1 inch pipeDiameter 55 and 65: 1P-2P air conditioning piping and bathroom pipingDiameter 75: 2P air conditioner cabinet - 5P air conditioner cabinet pipingDiameter 110-120: Wall switch wall concealed hole for wall switch inner boxDiameter 150: Hood pipe holeUsage: Put the center drill into the connecting rod, put in the set screw and twist it, then put the hole opener into the connecting rod and twist it to use.The product only contains: 1 square shank 400MM connector + 1 hole opener. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-DIMEANI official store