ProGear LX225 Cushion Deck Manual Treadmill with Additional Weight Capacity and Heart Rate System 4 Rubber Cushions are used to absorb leg, knee and ankle impact when exercising Cushioned Deck makes it easier on legs and ankles than walking outside Tested up to an extended 270 lbs. of user weight Twin 6" diameter flywheels provide an easy start and a smoother, quieter and more consistent workout Heart Pulse Sensors enables heart rate measurement to target your heart rate zone