THERMAFLEX S-LP-10, NON-INSULATED FLEX DUCTS ARE IDEAL FOR LOW, MEDIUM PRESSURE HEATING AND COOLING SYSTEMS WHERE INSULATED DUCTS ARE NOT REQUIRED. THESE HVAC DUCTS FEATURE A STRONG WOVEN FIBERGLASS FABRIC WITH A FLAME RETARDANT COATING THAT IS BONDED TO A CORROSION RESISTANT STEEL WIRE COIL FOR SECURE AIR SEALING. SPIRAL DUCTS WILL NOT UNRAVEL WHEN CUT AND HAVE A SELF-EXTINGUISHING INNER CORE THAT WILL NOT SUPPORT FLAMES. TEMPERATURE RANGE IS FROM -20F TO 250F. DUCTS MEASURE 2-14″ IN DIAMETER. GREENGUARD CERTIFIED.