The Nimbus Infinity opening system is a heat insulated aluminum door and window system with a hidden sash opening feature. Sash frames are not seen from outside and when the sash is opened the appearance does not change. Due to its reinforced medium frame bar, it is highly resistant to wind pressure.  It has a heat barrier of 24mm and a maximum glass thickness of 24mm. Inward, outward, and tilt & turn concealed sash opening options are available.