 The other end of the fitting has a single- or multi-barbed tube—a long tapered cone with ridges, which is inserted into a flexible hose.An adjustable worm drive screw clamp (or other type of clamp) is often added, to keep the hose from slipping off the barbed tube.Barb fittings can be made of brass for hot-water applications, and plastic may be used for cold water; brass is considered more durable for heavy-duty use.