The inner tent on the Air 400XL is breathable to prevent condensation building up and each bedroom has fabric and mesh doors that can be zipped closed. There is good head room in both the living area and bedrooms. The bedrooms are darkened to reduce the likelihood of you being woken by early morning light. HH fly sheet - withstands the most intense weather conditions. The tent and groundsheet seams are all fully taped. All the material used is fire retardent and tested to meet the EN 5912 European safety standard. The Berghaus Air 400XL is an update on the previous Berghaus Air 4XL and 4.1XL models - it features more head height living space and a new blue colour scheme. The Berghaus Air 400XL Tent is the latest addition to the Berghaus collection of inflatable Air tents. The 400XL sleeps 4 people but is a much bigger version than the Berghaus Air 400 This is a top quality inflatable tent. The Berghaus Air 400XL uses high quality TPU airbeams that are really strong. Waterproofing is to a high standard - the tent fabric is tested to a hydrostatic head of 6000 mm.