The Rabel 8400 is a Minimal Super thermal casement window system complementing the aesthetics of slim sliding in minimalistic buildings. Having an outer visible face width measuring 31mm it was possible to create an invisible opening window. Its minimal dimensions allow for composite constructions while still keeping a 31-35mm face width lines.

Through its innovative design a hidden drainage system has been achieved thus eliminating visible holes or plastic caps on the face of the profiles. Special provision has also been made to allow wall connection with and without the need of an architrave. On the outer side, the sealing joint has also been engineered so that no sealing materials are visible. To enhance aesthetics most of the glazing bit intersections have been eliminated by design.

As a standard, the system is supplied with a concealed mechanism coupled with a wide selection of handles. All common typologies have been accommodated and they are available in square design. Optionally it can be upgraded to incorporate a burglary resistant multipoint perimeter locking system and a choice of safety and acoustic glasses types, reaching up to 51 dB of sound insulation.