<b>Specification:</b> <br><br>· Inner duct: Perforated Alium foil <br>· Middle layer: Glass Wool （20kg/m³ density） <br>· Outer sleeve: 1 Alium + 1 Polyester lamination <br>· Tempreture range:-30℃ to 150℃ <br>· Color: black <br>· Size: 4 inch X 33.3 foot (10m) <br><br><b>Feature:</b> <br><br>1）Thick layer of Black PVC on this ducting prevents light leaks. Works with exhaust and intake fans, carbon filters and <br>hooded lights which are 4" in diameter. <br>2）Under the Black PVC layer our ducting is built with 2 layers of Aluminum Foil With a layer of PET and Steel Wire Helix to <br>preserve the shape,keep your ventilation system free of rips and pin holes. <br>3）designed for reducing noise from fans and carbon filter systems, can decrease the noise by up to 50%. <br>4）this Hon&Guan ventilation suits for HVAC, Bathroom, Greenhouse, Grow room and Tent and so on.