When you are transitioning from a round duct to a flat surface such as a plenum, you need a tab lock collar. These galvanized steel collars have flexible tabs that make it easy to conform to any surface so you can form secure HVAC connections. Our lock collars are designed to fit both pipes and flexible duct work with plenty of room between the bead and the flange. All of our lock collars can be attached to both lined and unlined plenums.

Tab Lock Collars