range hood duct: used for range hood or other home appliances to discharge ... , use for air ventilation in each environment .2,flexible ventilation duct's material is aluminium foil.3,Fireproofing,at high temperatures ... or in case of fire ,no toxic gas emitted 4,Easy to delivery .and easy to install .Round ... Pressure : 2500pa10,Standard Length : 10M ,or as ordered range hood duct