The O2ptima CM uses two integrated, chest-mounted counterlungs. The counterlung position keeps them as close to the diver’s lung centroid as possible, providing excellent breathing characteristics in a variety of diver positions.
The counterlungs consist of an abrasion-resistant outer bag and removable welded polyurethane inner bladders. The bladders are accessible through a zipper on the back side of the outer bag.
The bottom side of the counterlungs attach directly to the scrubber canister. The breathing loop hoses attach to the sides of the counterlungs using threaded connections.
The exhalation counterlung has an overpressure/dump valve located at the bottom of the lung. An internal water trap is located in the bottom of the exhalation counterlung to make de-watering the loop easy.
The counterlung outer bag also contains a zippered “kangaroo” storage pouch on the front for accessories, and an attached line cutter sheath.
