Sometimes, your counter lungs can be a pain. The bulky things take up a lot of space on your chest, they are annoying and can get in the way of you being able to access other important gear. The Back Mounted Counter Lungs for the Poseidon SE7EN quickly become a favorite of divers after a few uses. They are easy to manage, and the free space on your chest is liberating. For you technical divers out there who like the option of manual injection, that can easily be added on using the BMCL manual injection pack.