£20.81 inc VAT CorePlus DCEXT250 Drill Bit Extension Bar for use with CorePlus and other brands of dry diamond core bit systems with a 1/2in BSP thread. Use in conjunction with diamond core adaptors to extend their working length. With 1/2in BSP female and 1/2in BSP male threaded ends. Do not use with diamond cores larger than 78mm in diameter. Add to Basket Quantity