Lifespan Fitness X-41 Cross TrainerThe Lifespan Fitness X 41 Cross Trainer has a Variable Automatic Resistance feature which is a high quality electric motor that lets you level up your workout on the fly conveniently with just a touch of a button. Heavy Duty Magnetic Flywheel Variable Auto Resistance 46cm Stride Length Pulse Sensor Variable Automatic Resistance Our Variable Automatic Resistance system on the X 41 uses a high quality electric motor that allows you to change your