The NK4-280 Warm is a 2-ply fold-up door with two heat insulation layers. Due to its rigid 280 mm wide frame construction, it is particularly suitable as a large exterior door, e.g. in dockyards and aircraft hangars. The width of a single door can be up to 28 m, and the height 25 m. When using an elevating support post system with multiple doors, the door width is unlimited. The heat insulation characteristics of the NK4-280 Warm are excellent, the u-heating value is 0.66 W / (m2 * K). The benefits of the NK4-280 Warm are showcased best in objects were moisture condensation is heavy. The Warm's door fabric always comes UV-coated, and it is possible to add windows and burglary prevention mechanisms to it, as well. A touch screen control panel is one of the accessories available for this door.