Abstract: A universally articulable supporting sheath comprises an interconnected series of links, each having a convex spherical surface at one end, and a concave spherical surface at its opposite end. The concave and convex surfaces mate with one another to form the sheath. Special links having branch openings may be provided. Various forms of waterproofing seals are provided, including O-rings, axially compressed rings, flexible belts, and ridges on the spherical surfaces. The links can be fitted together by thermal expansion. However, an axilly split link is also described, which comprises two parts which snap together. The split parts may be molded as a unit with an integral thin wall hinge. The bending characteristics and bending radius of a sheath can be modified by insertion of spacers between the links at selected locations, or by the insertion of pins into radial holes provided in the links.