UHMW, or ultra-high-molecular-weight polyethylene, is a subset of the thermoplastic polyethylene. It features extremely long chains and as a result is a very tough material, with the highest impact strength of any thermoplastic presently made. Some trade names for UHMW include BRAXX, FELXIFEND, GUR, Lennite, LubX C, LUNS, POLY FEND, Polystone M, Ramex, Tivar and ULTRA FEND.