The concealed frame system, available in the N14 200 and N14 300 variants, has a sash depth of 70mm and 80mm, respectively. Manufactured with thermally improved three-chamber profiles, it uses 24mm and 34mm polyamide bars reinforced with fibreglass. With a 66.5mm wide sash, this system features the concealed frame, which allows maintaining the same view in both fixed and moveable sections.