This is a very slim window with a construction depth of 71 mm. The rounded edges of sash and frame match design style home soft perfectly. KF 310 is available in the classic UPVC version or as UPVC/aluminium window. The aluminium clad on the outside can be designed in many colours. The new 6-chamber frame profile ensures even better thermal insulation. Three continuous gaskets protect the inside area from the wet and improve thermal insulation and sound reduction at the same time.