Made with  DULL NYLON fabric and “INFLATABLE SYSTEM”
waterproof/wind-proof/water repellent/transpiring

Dull Nylon fabric consists of two coupled layers: Dull Nylon fabric outside and hydrophilic membrane inside. The membrane ensure all the practical characteristics for outdoor or indoor use. Dull Nylon looks and feels more like fabric than normal nylon.
Inside with INFLATABLE SYSTEM  lining with valve to inflate and deflate air, made of Nylon jersey fabric coupled with a breathable and waterproof membrane.  The temperatures may easily be regulated by inflating and deflating the interior from about -15° C to + 15°C.
Air is the best  and more eco-friendly thermal insulation.