A glass packer, window packer, or U packer is a small plastic or rubber wedge-shaped piece that is used to provide support and levelling for windows and glass panels. These packers are commonly used in construction and renovation projects to ensure that windows and glass panels are properly aligned and securely in place.

The packers are typically installed between the window or glass panel and the frame to provide a cushioning effect and prevent damage to the glass. They are available in a variety of thicknesses, typically ranging from 1mm to 10mm, to accommodate different sizes and types of windows and glass panels.

The U-shape of the packer allows it to fit securely around the edge of the window or glass panel, and the wedge shape provides the necessary support and levelling. The packers can be stacked on top of one another to provide additional support and to level the window or glass panel as needed.

Using packers has several benefits, including:

• Improved Window Functionality: Window packers can help to ensure that windows and glass panels operate smoothly and without issue, by providing the necessary support and alignment.
• Improved Insulation: Properly installed packers can help to improve the insulation properties of windows and glass panels, by ensuring a tight and secure fit between the glass and the frame.
• Reduced Risk of Damage: Glass packers can help to prevent damage to the glass or the frame by cushioning and supporting the glass and preventing it from rubbing against the frame.

Overall, glass packers or window packers are a simple yet effective solution for ensuring the proper alignment and support of windows and glass panels, which can help to improve the overall performance and longevity of these components.