... interface SELECT, START and STOP keys, 6 speed/slope keys, speed/slope tuning key Emergency shutdown key, built-in axial flow ... fan.fan control key, speed/slope ± key on armrest.2 built-in speakers, MP3 audio ... programs, each having 10 difficulty levels; 1 custom program.Slope 0-15%Speed range 0.8-18KM/HHeart rate ... / home use 3.0HP foldable treadmill fitness equipment for sale