Milliard 5-Inch Duct Flange Multi-purpose. Use it with any 5in. air duct system. Great for home & garden use. Professional and durable. Designed for use with Milliard 5in. Ducting Clamps. Installs quickly over pre-existing holes or ports and can be fitted to a variety of applications or materials. Includes flange, collar fitting, and installation screws.