How to refuel the upstart treadmill? Where are the air holes?

New noble Treadmill at the Front of Runway How to refuel at the Front of Treadmill? Treadmill is a routine fitness equipment in family and gym, the simplest one in today's family fitness equipment, and the best choice for family fitness equipment. 1965, the world's first household treadmill was born in Tantelli, northern Europe, and the designer modified it according to the principle of speed transmission belt.