Mueller's Standard Heel Cups are lightweight and designed to fit into most shoes. The contoured shape protects the heel and helps to help prevent shin splints and heel spurs. The comfort cell design helps to absorb the shock of heel strike and can help with heel and knee pain, while also being of assistance with the agonising pain of Plantar Fasciitis and Sever's disease which is a common growing injury in children. Regular = under 175lbs/80kgs Large = over 175lbs/80kgs Mueller® pro heel cups are also available and provide heavy duty protection for the pain of heel strike during sports activities.