The Sole Fitness F85 Treadmill incorporates all the specs of the F83 plus features the highest horse power motor that Sole offers. It has an impressive 4.0 HP Continuous Duty HP motor with output and performance second to none. An exceptional 22inch wide running surface that is comfortable for any runner and the six auto programs and two user-customized workouts are yet another features. Just press a button and take your stride to speeds up to 12 mph. The F85 can handle users weighing up to 400 lbs and also has two separate heart rate control programs. The product is fully equipped with all the programs and customization you'd expect. You can be assured of the most efficient and safest workout possible as the heart-rate control option automatically calculates your recommended target range based on your age. Other features include a low-noise deck, Cushion Flex shock absorption treadmill deck, our longest commercial-sized belt and low-profile running hood. The product also has speed and incline controls on the arm rests as well as built in cooling fans for comfort. The treadmill offers user friendly console with a vibrant display that includes a message board for clear instruction and feedback. There is also a 1/4 mile track feature and a Peak and Valley graph for different programs. The built in speakers which allow you to hook up any MP3 player (iPod, etc.) for easy listening are yet another features.