Stainless Steel band with clamp that secures Flex Duct or rigid round duct connections. The band is secured in place at the bridge by a slotted hex head screw. This zinc plated carbon steel screw can be flipped up away from the band to offer a quick release when adjustments are needed. Dyna-Clamps are available in stock sizes ranging from a 7’’ diameter to 20’’. Two or more clamps can also be connected together to accommodate duct diameters over 20’’. Usually in engineer’s detail drawing, specs, or mechanical note: All flex duct connections to be made with stainless steel banding/clamps. Sizing based on max diameter that the stainless band can accommodate. Each size draws down 2-1/2″ in diameter.