The document describes the G2/131 Gas Permeability Tester manufactured by Labthink Instruments Co. It can simultaneously test up to 3 specimens to determine properties like gas transmission rate and permeability coefficients at different temperatures. It uses differential pressure to test a variety of materials like films, composites, and foils. The instrument has intelligent software, embedded computer control, and data sharing capabilities. It conforms to various international standards and can test various gases on a wide range of materials.