These special flexible shafts do not have a handpiece for tool mounting and are particularly flexible in the front section. The POLISTAR-TUBE grinding tools are attached directly to the core of the flexible shaft with screws (INOX type) POLINOX cross buffs PNST are screwed on with adapter AD M4 or AD M5 (accessories) This combination is highly suitable for gradual fine grinding and cleaning of inner surfaces of pipes and pipe bends. Both pipe bend ends can be deburred from the entry side. The PST-T flexible shaft is suitable for grinding the insides of pipes.