Connected with the harness and working against the inertia of up to four heavy steel flywheels, the kBox allows you to put an extreme workload on your muscles in the lower body. Designed around the principle of flywheel training, there is no upper limit in how much kinetic energy you can produce, in the flywheel motion. With low inertia and low effort you will in the same setting have a gentle but effective rehabilitation exercise for an injured athlete or postoperative patient.