Features:- This is a brand new item- Easy to use， high quality. good performance， long life- Excellent for making clean and accurate hole on glass ， tile and marble- Works better with a electric drill( Excluding in this item )When using the bit please add water to cool down the temperature to extend its service lifeSpecifications:Material: MetalSize: 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12mmPackage Includes:1 x 10pcs Diamond tool drill bit hole saw set