Tuli's Double-Ribbed Heavy Duty Heel Cups are the most advanced shock absorbing heel cups available today. The primary force of the heel strike is absorbed by the larger and higher waffle pattern while the lower and denser waffle pattern absorbs the "high pressure" and final force spike of heel strike. Perfect for sports activities. 
 
Sizing:
Small - less than 36kg
Medium - less than 80kg
Large - greater than 80kg