20-Level Auto Incline (2-20%)This treadmill with auto incline simulates real terrain with 20 adjustable levels, ranging from 2% to 20%. Whether you're walking, jogging, or sprinting, the incline helps boost calorie burn and activate more muscle groupsperfect for home gym & commercial treadmill indoor treadmill workouts. 99.8% Accurate Heart Rate MonitoringFeaturing Advanced Green Light Sensor Technology, this treadmill provides highly accurate heart rate tracking at 99.8%. Monitor your heart rate, speed, distance, time, and calories in real timeideal for both treadmill running and casual walking.