12-pc Rectangular Food Container with Green Lids. Air tightness criteria is determined by WVTR. Why 0.05g? WVTR is a test level, the lower the criteria, the better airtghtness and freshness. (WVTR: Water vapor transmission rate). Excellent solutions for food storage. Supplying the highest quality products "lock and lock" airtight containers for food storage. The containers are scientifically designed for stacking both upward and sideways to save space on the shelf.

12-pc Rectangular Food Container with Green Lids. Air tightness criteria is determined by WVTR. Why 0.05g? WVTR is a test level, the lower the criteria, the better airtghtness and freshness. (WVTR: Water vapor transmission rate). Excellent solutions for food storage. Supplying the highest quality products "lock and lock" airtight containers for food storage. The containers are scientifically designed for stacking both upward and sideways to save space on the shelf.