The 2000 SR Series Ducting is specifically engineered to handle unconditioned are. The 2000 SR Series can withstand high heat- high humidity and excessive CFM's without any duct failure or fatigue. 2000 SR features a triple laminate with industrial grade foil casting for durability- and an ultra-smooth double sealed core for frictionless and silent air flow. The "Carbon Black" inner core does not reflect light. "Rip-stop" prevents tearing- galvanized spring steel maintains duct shape and prevents rust. The SR Series is c-ETL-us certification tested and verified to conform to UL181 standards. Made in Canada! North America's best quality product. It's engineered for what you need.