Champion Door solutions with elevating support posts are ideal for extra wide and extra high doorways. The large partition-free doorways of aeroplane and helicopter hangars and specialised machine rooms require doors with special properties. The NK2 Double and NK4 Warm models have been designed specifically with larger industrial doorways in mind. Their rigid frame structure makes them ideal for use as large external doors. The NK4 Warm comes with two additional insulation layers for added thermal insulation and soundproofing. The PVC material is designed to resist the chemicals used for de-icing aircraft and withstand violent winds.