core kit cutting hard material,such as stone,granite..very good performance. Speed very fast,with chip out when working. Long core kitThis core kit model number DBSET04 Comprising:3-pcs core drill: 52X150MM, 65X150MM, 117X150MM4 Accessories:Hex adaptor 90mm, pilot drill8X200mm, SDS-plus extension 150mm, drift key, with a alumnium case