... national patent (patent No.: ZL2007203106592).Very light,save much place and water, very suitable for mid-small room.Fast fold ... needs to be added 60% water=150 liters (0.15 tons), save water reach to 60%.Save space: after being folded,thickness ... effectMore than 1 hourFeatureFolding, Removable, Portable, Simple operation, Save water and space, Lasting heat insulation ect Service lifeOver 10 years ...