The faithfull faidckit11 11 piece diamond core drill kit is suitable for brick and concrete blocks etc they are ideal for plumbing electrical engineering installation and general building tasks all cores are 12 inch bsp threaded with 8mm turbo segments set contains5 x diamond cores with 8mm turbo segments sizes 38mm 52mm 65mm 117mm 127mm1 x sds plus extension adaptor 10mm x 115mm1 x hex extension adaptor 12mm x 88 mm1 x sds plus extension adaptor 10mm x 240mm1 x hex extension adaptor 12mm x 240