CONNECTION BETWEEN INSIDE AND OUTSIDE The folding door systems are based on the hinged systems. A special hardware system allows the leaves to be folded in the form of a booklet, thus achieving a maximum opening of the opening. OPENMAX PREMIUM, the new multi-leaf generation OpenMAX Premium is an innovative modular system that works in a unique way; its secret is in the name, each leaf is placed and slides independently, transforming spaces between rooms or exits to the garden or terrace. Unlike the traditional folding system, OpenMAX Premium goes unnoticed indoors, creating large and open spaces, its exclusive system allows each leaf to open independently, facilitating cleaning and ventilation. In short, simple lines and minimal structure for an extremely versatile and safe system. WHY SUMUN? They save energy. The technology of SUMUM PVC doors can save up to 68% of your energy bill. They insulate from noise. Silence is comfort. With SUMUM doors you can reduce exterior noise up to 32 times (50dB). They provide security. SUMUM PVC doors are equipped with top brand reinforcements and hardware, making them very secure. They are insulating. They protect us from the cold, heat, rain and wind. We will be comfortable regardless of the weather outside.