The Broadfix U Packers have been manufactured with a high percentage of post-industrial and post-consumer recycled material and are completely waterproof. Being made from plastic, they do not shrink, rot or swell. Broadfix U Packers are capable of withstanding higher compressive loads than traditional timber flat packers making them more economical. The ever-popular U-Shim is perfect for shimming behind a screw or fixing ? loosely install the fixing, and then simply slide the required number of U-Shims over the fixing. The unique comb/clip prevents the U-Shims from falling out, which leaves both hands free to tighten up the fixing.