R-Value = 15.67 unaffected by humidity : Prevents condensation : Prevents 97% of radiant heat transfer Vapor barrier Elastic 19dba contact noise reduction UV resistance Seals around nails (no leak) Reflective aluminum foil on each side of 3mm (13/64) closed-cell polyethylene foam center Keeps its shape over time (doesn't collapse)Rippled surface increases airflow 1/8 inch thick Non-Perforated White Finish Additional Details ------------------------------ Product description: R-Value = 15.67 unaffected by humidity : Prevents condensation : Prevents 97% of radiant heat transfer Vapor barrier Elastic 19dba contact noise reduction UV resistance Seals around nails (no leak) Reflective aluminum foil on each side of 3mm (13/64) closed-cell polyethylene foam center Keeps its shape over time (doesn't collapse)Rippled surface increases airflow 1/8 inch thick Non-Perforated White Finish