The new EgoKiefer XL® window technology in vinyl offers added value in three ways. More design: The profile geometries are significantly optimised by the innovative adhesive technology. The narrow design of the EgoKiefer XL® window technology opens up new perspectives in façade design. More light: Due to the increase in the glass ratio by up to 15%, the XL® offers more light incidence than conventional window systems, and thereby a noticeable improvement in the living/working atmosphere. More heat: With XL®, the loss of heating energy through the window can be reduced by more than 70%.