Many transfemoral amputees use subatmospheric suspension using a hand pump rather than an automatic pumping system such as the Harmony or electirc pump. Stan Patterson recommends a distal air chamber as a vacuum accumulator when using a hand pump. The Smart Pump is a component designed by Clint Accinni, which is a modular distal air chamber. According to Clint it is super easy to install and eliminates the difficult and time consuming fabrication of an air chamber. Once the prosthesis is complete with the Airpuck, it can be easily converted to a "Smartpuck" electronic pumping system if necessary or desired. The Smartpuck has the same dimensions and uses the same fabrication dummy and attachemnt system as the Airpuck. Build height for either component is 1 3/4 inches. By the way, Clint says the Samrtpuck does alot more than just pump air. It collects lots of data which can be used for assessment and outcomes. All of the Smartpuck functions are controlled through a mobile phone app. For more information Contact Clint Accinni.