The Faithfull FAIDCKIT7 7 Piece Diamond Core Drill Kit for cutting clean holes in brick and concrete blocks. They are ideal for plumbing, electrical, engineering installation and general building tasks. All cores are 1⁄2 inch. BSP threaded with 8mm turbo segments. Set contains:3 x Diamond Cores with 8mm Turbo Segments: 38mm, 52mm, and 117mm.1 x SDS Plus Extension Adaptor 10mm x 200mm.1 x Hex Extension Adaptor 12mm x 200mm.1 x A-Taper Pilot Drill 10mm x 200mm.1 x Extractor Drift Key.1 x Carry Case. ROTARY USE ONLY – Must not be used on Percussion/Hammer mode. DO NOT USE DIAMOND CORES LARGER THAN 78mm IN DIAMETER WITH SDS PLUS DRILLS AS THIS MAY RESULT IN DAMAGE TO THE POWER TOOL OR SDS ADAPTOR. Diamond Cores give the best results when used with a purpose built core drilling machine.