◆ This is a used ring for both ends of a warm air duct. ◆ You can create a warm air duct much cheaper by purchasing aluminum ducting at a home center and having them set the rings on both ends, compared to buying a warm air duct product. ◆ If you are looking for a replacement ring due to damage, or if you are a DIY enthusiast, please consider this. ◆ I am also selling duct stands. Feel free to comment!