What is the moisture barrier membrane made of?

• A. Enhanced biocomponent core ePTFE film (ePTFE = expanded polytetrafluoroethylene)
• B. Nylon film
• C. Polyurethane layer
• D. Polyethylene laminate

Answer: (A)

The moisture barrier membrane is made of expanded polytetrafluoroethylene (ePTFE). This material provides a breathable yet waterproof barrier: its microporous structure blocks liquid water from passing through, while allowing water vapor to escape, keeping you dry and comfortable. Nylon film, polyurethane layers, and polyethylene laminates are different materials used in other parts or configurations, but they don’t offer the same balance of waterproofness and breathability as ePTFE.