Abstract: A water supply line includes a cylindrical and ductile outer tube that has a centrally aligned axis. An inner tube is concentrically spaced about the axis of the outer tube and has a length coextensively sized therewith. The inner tube is equidistantly spaced inward from the outer tube, defining a cavity therebetween. Fingers are intercalated between the inner and outer tubes and seated within the cavity. The fingers extend outward from the inner tube and are positioned along the entire length of the tubes, defining isolated air chambers which act as a thermal blanket, preventing cold air from passing into and hot air from exiting the inner tube. A coupling is provided with a bore and is in fluid communication with the inner tube and conjoinable therewith. The coupling has an outer surface provided with barbs such that the coupling can be connected to the inner tube.