An inflator reg combines a backup regulator with a BCD's buoyancy control system in one compact, at-the-ready unit. SCUBAPRO introduced the inflator reg concept to diving almost 30 years ago with the AIR2 (short for Alternate Inflator Reg). Now in its 5th generation, the AIR2 delivers air as smoothly as most primary second stages, and unlike traditional dangling octos, it is always within easy reach if needed. As a BCD power inflator the AIR2 fits comfortably in the hand, and the large inflate and deflate buttons can be differentiated by both color and touch, improving safety on ascents. The AIR2 was diving's first inflator reg and, with five generations of improvements, it's still the best.