The Nautilus / Stairmaster 4600CL is a cordless unit and features new easy-grip upper-body handles which provide maximum user comfort and ergonomically designed side handrails to accommodate a wide range of fitness levels. Contact heart rate, integrated right into the upper handlebars and is easily accessible runs the units heart rate training program. The Stairmaster 4600CL reading rack accommodates larger reading material with a built-in cassette and water bottle holder mounted to the unit?s consol, which also features a pivoting head that reduces glare and accommodates users of all heights, a built-in entertainment system that provides volume and channel control for wireless commercial entertainment systems (for club use only).