U Packers – Polypropylene – Residential & Commercial FramesProduct Overview These Grey U Packers are designed for the precise positioning of window and door frames. They easily slide around existing fixings without the need to remove screws, ensuring accurate datum and line during set out. Each packer is color coded for quick on site identification, providing a stable bearing under typical frame loads. The internal comb design ensures a secure grip to resist movement during tightening and final fixing. The