... for hot air Good Flexible Aluminum Foil Duct For Ventilation System 1.Material:aluminum foil2.Features:aluminum foil with steel ... wire inside,perfect flexibility,extension rate 1:23,temperature range:-30 to 140 degree.max air flow:30m/s, ... used in hgih pressure,low pressure air conditioner and ventilation system,easy installation,graceful appperance,anti_temperature and inflaming retarding etc.5 ...