Knee Protection Technology: Designed with your safety in mind, our treadmill features silicone shock absorbers, shock-absorbing cushions, and a 5-layer non-slip walking belt to minimize knee impact. 4-in-1 Functionality: Tailor your workout to your needs with adjustable speeds: 4-8 km/h for running, 3-5 km/h for walking, and 1-2 km/h for working.