Birko Sport Two Part Insole | Cork/EVA"The BirkoSport insole system was specially designed with the requirements of physical activities in mind. The anatomical shape and deep heel cup stabilize the foot and improve pressure distribution. The preformed BirkoZell upper shell is flexible and has excellent shock absorbing properties, for improved foot support during physical activities. The rigid BirkoKork core gives the heel the necessary guidance and stabilization. The optimally coordinated