17 Plastics in extruded form for use in manufacture, particularly for fixing, bundling, enclosing or connecting cables, cable joints, tubes or pipes; Flexible pipes not of metal; rings of plastic; seals and sealing rings for connectors; sealing plugs of plastic; seals for pipe connections; connecting hoses for vehicle radiators; joint packings for pipes; insulators for cables; cable bridges of plastic for protecting cables; non-metallic fittings for flexible pipes