This FAITHFULL diamond core Extension Adaptor has 1/2in BSP Female and 1/2in BSP Male threaded ends, it is to be used in conjunction with the Faithfull FAIDCHEXADAP and FAIDCSDSADAP diamond core adaptors to extend their working length. Specification Size 1/2in BSP Female and 1/2in BSP Male threaded ends x 250mm.