The Ideal-Air Gro-Sok is designed for the optimal air distribution. It is lightweight, draft free, condensation resistant, machine washable and anti-microbial. It is quick and easy to install. With ?no noise technology? you will be assured of quiet operation. Ideal-Air has designed the Gro-Sok using heat load and duct design technology to provide even and efficient air flow. You?re assured of getting the greatest air distribution benefits more efficiently, which reduces operating costs. Proper duct and equipment sizing is critical to a successful environment. This standard kit contains a 20 foot long by 12 or 16 inch diameter duct sock, end cap, cable and hanging hardware. This system is designed to be used with the Gro-Sok transition system and can also be used with conventional metal ductwork with a CFM range of 1600 - 2000 for #700854 and CFM range of 800 - 1200 for #700853.