This is the Spare Air NITROX Submersible Air Systems Package. This spare air set features: Comes complete with Yoke Refill Adapter Safety Leash (Prevents Accidental Loss) Deluxe Holster The answer for out-of-air emergencies Added comfort when using rental equipment Easier than an octopus Light weight and compact, only 2 lbs Great for traveling Pass your Spare Air to your buddy Simply put the Spare Air in your mouth and breathe 3.0 CF - about 57 Breaths at the surface It is nice to have a little extra insurance when diving.