TgForce 3D Impact Running sensor/tracker. This device straps onto your lower leg and provides real-time feedback regarding running impact and cadence. Pairs with its free app from the Apple store to provide feedback to help you transition to low impact running. Great for anyone trying to prevent injury or coming back from injury. Comes with the instruction manual, sensor, adjustable strap, and charging USB cord. Retails for $179 not including shipping. Only sold on the company's website. *** PLEASE NOTE THE APP IS ONLY ON ON THE APPLE STORE AND ONLY USEABLE WITH APPLE iPHONE 5s OR NEWER, iPAD, or iTouch 6th Gen!!! ***