The Faithfull FAIDCKIT7 7 Piece Diamond Core Drill Kit for cutting clean holes in brick and concrete blocks. They are suitable for plumbing, electrical, engineering installation and general building tasks. All cores are 1andfrasl;2 inch. BSP threaded with 8 mm turbo segments. Set contains: 3 x Diamond Cores with 8 mm Turbo Segments: 38 mm, 52 mm, and 117 mm. 1 x SDS Plus Extension Adaptor 10 mm x 200 mm. 1 x Hex Extension Adaptor 12 mm x 200 mm. 1 x A-Taper Pilot Drill 10 mm x 200 mm. 1 x Extractor Drift Key. 1 x Carry Case.