This set includes 30mm, 40mm, 50mm core drill bits, SDS+ chucks, guide drills and a 350mm SDS+ extension shank. Hardened metal, carbide tipped high quality tungsten, long service life. Suitable for brick walls, red bricks, masonry walls, foam bricks, hollow core drills, etc. It can be used to install air conditioners such as air conditioners, extractor hoods or washing machines. The teeth of the drill bit are sharp, the vibration is small during the opening process, and the operation is steady. Rounds off alloy blade combinations, with each blade bearing a portion of the workload, not likely to tear. Professional-designed drain holes ensure smooth chip removal during of the opening. Comes complete with core drill, pilot drill and SDS arbor, easy and quick to drill. Low pressure is key to prolonging cutter tip life and achieving a straight cut. they cannot be used for concrete, load-bearing walls, walls with steel bars. Advantages: 1. Made of high quality carbide tipped metal, very