Our ducting is some of the strongest available on the market, at an unheard of low price. It is 25 feet long. It accommodates HID Hut air cooled reflectors, and accommodates HID Hut Carbon Filters. It has extra thick 3.5 mil single ply foil, not laminated and glued layers of foil that degrade with time. It is reinforced with high tensile steel wire and so thick that light does not penetrate it!