Spare Air provides a totally redundant air supply back up in case of an out-of-air emergency. No buttons to press, no knobs to turn, just bite the mouthpiece and inhale when you need it. With 1.7 cu. ft. of air, your Spare Air pony bottle will give you approximately 30 surface breaths (actual breaths will vary by individual and depth). It's easy to refill your Spare Air from a full 3000 psi scuba tank using the refill adapter (Not included)

Includes: 1.7 cu. ft. dive cylinder