an air packaging device comprises two layers of thermoplastic films , which form a sealable space where air is fulfilled after a 1 st and a 2 nd steps of heat - sealing process , includes a number of independent sealed air chambers and a main air passage channel . the main channel has an air inlet . each sealed air chamber is connected with the main channel by at least one of one - way valves each consists of at least two layers of plastic films . at least two of one - way valves are installed inside of the air chambers . this air packaging device increases the cushioning protection where the protection is most needed , but can reduce air chamber dimension at the less important location in order to reduce the volumetric size and hence reduce the shipping cost .