Product details of HKS 55cm Exercise Fitness GYM Smooth Yoga Ball Blue

Smooth Surface
100% brand new and high quality
Material:PVC
Diameter:55cm/21.7"
No air
This diameter is  the tile size not aeratedthe diameter of the inflated ball will become      smaller.depend on the circumstancesthe size may differ about 10cm/4" 

Specifications of HKS 55cm Exercise Fitness GYM Smooth Yoga Ball Blue

What's in the box: General Features:
SKU NO037SPAA4C35NANMY-8632275
Size (L x W x H) 10 x 10 x 5
Weight 0.05
Warranty period No Warranty
Warranty type No warranty information provided