Features: Size: 30mm ( 1-3/16" ), 40mm（1-9/16"),50mm(2"), 65mm(2-9/16"),1x 220mm 8-7/10", 1x center positioning drill bits (110mm 4-5/16"), 1x Screw,1x Key Wrench. This concrete hole saw set is selected of steel, high hardness, rust prevention, and durability, The hole saw comes with a ventilation holes, Easy to remove dust and effectively improve work efficiency. Suitable for multiple materials, such as hollow brick, cement wall, concrete wall. Can be used to install openings for air conditioning, range hoods, water pipes, water heaters, smoke pipes, sewers. Equipped with a hole saw drill bit, suitable for all major manufacturers, Adding coolant during continuous high-speed drilling, It can prevent the drill bit from burning, Increase the service life of the product. This Concrete Hole Saw Kits comes with a portable storage case for convenient use and store. Specifications: Component:Cemented Carbide+Tungsten Steel Size:Approx.220mm/8.66inch Package Includes: 1 Set Concrete Hole Saw note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.