Simple interlocking metal flexible conduits coated in smooth black PVC. Made from a helical ribbon of Sendzimir continuous hot-dip zinc coated strip (UNI EN 10346), selfextinguishing PVC, with a smooth external surface and thread fastening. Resistant to most types of oils and greases, they are extremely flexible and have excellent levels of mechanical resistance. The progressive length reference marked on the coating surface, facilitates the cutting, and costantly updates the remaining quantity contained in the coil.