AirBAPS allows limitless combinations of proprioception, stability, and strengthening. 20" board has same advantages and maintains same shape of original BAPS system, including a single, non-adjustable pivot point. Inflatable bladder on top easily inflates/deflates to control level of instability. Vectors printed on bladder aid in properly positioning foot on board. As foot is aligned with different vectors, stresses from exercise will change to isolate ankle, knee, hip, or back as well as varying degrees of ankle plantarflexion, dorsiflexion, inversion, and eversion. Includes pump and pressure gauge for accurate, repeatable inflation. Ships fully assembled and includes protocol/application manual authored by inventor, Gary Gray, PT. One-year warranty.