This is a replacement union. If for some reason your union gets damaged or lost, here is a replacement union. ALL OF OUR PRODUCTS COME WITH A DRYER SIDE UNION AND WALL SIDE AS A SET, DO NOT ORDER THIS IF YOU ARE ORDERING ONE OF OUR COUPLINGS. This Dryer Side Union is found on the MV-Flex, but will also work with the MV-90 and MV-180 if trying to convert to an MV-Flex style non-self-aligning installation for offsets greater than 3 inches. The MV-Flex Dryer Side Union comes with 2 hose clamps for you to attach your own minimum length of transition duct.