A urethane-coated polyester blower hose, Springflex FX-400 has closely sewn flap construction and a smooth interior for optimum airflow. Suited for temporary heating applications, the duct has a belted cuff to ease attachment to the heater and a safety-orange wear strip for drag resistance. Moisture-resistant and UV-stabilized to prevent mold and mildew, the portable heater duct operates from -60 to 400°F (-51 to 204°C) and is flame retardant per ASTMD6413. It is offered in 12 to 24” dia. sizes and 25’ lengths.