This is a dual lumen conserver cannula. This type of cannula is typically used with a pneumatic conserver. As a dual lumen conserver cannula, this product helps your pneumatic conserver detect the end of your inhalation process, so it knows when to cut the flow of oxygen as a conservatory measure. This cannula has been manufactured using extra-soft, flexible plastic to provide a very comfortable fit. To increase your comfort when using this product, this cannula fits around your ears to secure the cannula in place, giving you a more full range of motion. This cannula comes with either 4' or 7' of tubing.