U-Bar constructed of high-grade carbon alloy spring steel 50CrV4 which is heat-treated and hardened to Rockwell standard HRC45. 50CrV4 is a fine grained, highly abrasion resistant carbon-chromium alloy steel. Very good shock resistance and toughness are also key properties of this alloy in the heat treated condition. Commonly employed in heavily stressed machinery parts including shafts, gears, pinions and also in hand tool components. White baked on enamel finish, markings engraved in U-Bar. The lock is made of aluminum alloy with surface oxidation. Numbered steel braided aircraft cable with bullet tip is an integral parts of the locking system. Braided cable frays when cut, making re-welding impossible. Same numerical sequence appears on all three components for added security. Lighter in weight yet stronger than all previous models. Designed to fit most Swing Door Conveyances. (20', 40', 45', 48', 53'). Must be purchased in lots of 20.