assembled hvac duct collar 10 the flange 26 allows at least one joining mechanism not shown to be inserted through its body so as to ensure the assembled hvac duct collar 10 will stay in a stationary position when successfully installed into a wall ceiling or other surface each flange 26 is located at or near within approximately an inch of the edge of the circumferential segment 22 that it extends from laterally positioning the flange 26 at this location allows for the use of a cover not shown or other similar additional element over the hvac duct collar 10 in certain instances when the hvac duct collar 10 and all associated ductwork is installed one of ordinary skill in the art will see that each flange 26 could be located anywhere along the body of its respective circumferential segment 22 while still adequately performing its function it will be understood that the flange 26 is an essential element in creating the assembled hvac duct collar 10 without a single flange 26 the assembled hvac duct collar 10 is simply an hvac conduit referring to fig1 through 5 a locking mechanism set having both a first locking mechanism 32 and a second locking mechanism 34 is found at both ends of the length of the strip of.