Vertebra for articulatable shaft

A vertebra for use with a plurality of identical vertebrae to be arranged in a series at one end of a shaft which is capable of flexing or articulation under remote control, the vertebra having a generally circular outer rim, an inner hub region, and a plurality of webs or spokes interconnecting the outer rim and the inner hub region, the inner hub region presenting a projection on one face of the vertebra and a recess on the other face of the vertebra, both the projection and the recess having continuous, unbroken surfaces, the projection and the recess being of complementary shape and being such that when a plurality of vertebrae are arranged in a series, the surfaces of said projections and recesses inter-engage to permit rocking of one vertebra on the adjacent vertebra to provide said flexing or articulation, each vertebra comprising a single, unitary, molded plastic piece-part and a circular hole is provided between two adjacent webs or spokes for the passage of pipe, and the hub region is imperforate.