Notice: S for 20kg-40kg physique weight(44lbs-88lbs); Foot length:21cm-21 M for 30kg-50kg bodyweight (66lbs-110lbs);Foot length:21 L for 50kg-70kg physique weight(110lbs-154lbs); Foot length:23cm-24cm XL for 70kg-90kg physique weight(154lbs-198lbs); Foot length:24 XXL for 90kg-110kg body weight(198lbs-243lbs); Foot length:26,Relieve the surprise and vibration with A shock-Absorbing Device(Flexible Spring) 2,Easy to apply with sneakers on, appropriate in your weight and the lenght of foot 3,More calories and higher health can burn for adults via this way For children, it's helpful to promote blood circulation and the expansion of ossature, and then is helpful to be taller 4,Whether for jogging, running or even walking,Shoes defy gravity with each fun-filled step They are really easy to balance on, soon they&;ll be bounding around like an astronaut on the moon it&;s clean to burn calories, build fitness, coordination and toughen leg muscle tissue