A five-chamber system with a construction depth of 70 mm with the possibility of using fillings up to 41 mm wide. The IDEAL 4000 series is a basic proposition in the field of aluplast external door solutions. Thanks to the multi-chamber structure with a depth of 70 mm and the use of a door threshold with a thermal insulation spacer, they have very good thermal insulation parameters. The use of steel reinforcements with large cross-sections and the use of weldable corner connectors guarantee appropriate static and strength parameters.