Nautilus Commercial Series E916 Elliptical TrainerItem Condition: Used Good condition, technician tested, aesthetic blemishes, normal wear and tear. The patented four bar linkage system, built into each foot pedal, follows the natural movement of the feet during the entire elliptical motion. Because users will feel more comfortable, their workouts will be more challenging, leading to better results. The articulating foot pedals also keep hips, knees, and ankles properly aligned. Commercial quality