Weatherseal performance matters in windows, that's why the Diamond Suite is supplied with Q-Lon pre-inserted into all sections.
The charts below show the compression performance and set when compared with competitor gaskets, this demonstrated the recovery of the gasket after compression thus ensuring consistent performance after your windows are opened and closed, particularly if they are left closed for a long time.

The graph below shows the weather performance against competitor gaskets and demonstrates that Q-Lon provides less air leakage over a wide temperature range when compared to our competitors.
