The Restop 2 uses a patented "bag within a bag" design to safely contain and neutralize human waste. Restop contains the odor as well as the waste. The outer bag is a Mylar gas-impervious bag. Designed to be used with any commode system or can be used directly on the ground in wilderness situations.When done, the upper bag folds into the lower triple layer barrier bag which then zip locks closed for complete containment.