Perma Duct Premium Reinforced Air Duct offers superior performance in premium air ducting. Though it is value priced, it is comparable to the leading premium ducting on the market. This ducting is airtight, easy to install, and resists tearing and punctures. The smooth interior also aids in keeping noise to a minimum. It is available in six different sizes, and sold in 25' lengths. Set of 2 stainless steel clamps included.