You have the choice between 3 different IPS (Impact Protection System) springs, which correspond to 3 different user’s profiles:
The XR series:
Feature the Standard IPS, for adults and teens, which can be used by anyone, whatever your weight (min weight 70 lbs – 32 Kg). No problem if you are a heavy person. If your weight is well above average, you will however get less rebound effect and might consider opting for a Pro model.
The Pro series:
Feature a quite harder IPS. It is suitable for heavy weight individuals and/or athletes who want a harder workout or do extreme sport.
The PowerShoe series:
Feature a softer IPS suitable for pre-teens and teens, weight range about 40lbs (18Kg) to 120lbs (55Kg)