They effectively relieve pain caused by the boots pressing against and rubbing the inside and outside of the ankle.Placed underneath the sock, these protectors stay firmly in place throughout any sporting activity. Varying-thickness gel: 2 mm at the edges and 4 mm in the middle, for improved protection. Re-usable Hand-washable with household detergent for a better hold Dimensions: 50mm diameter. Silitene protection specially designed for the ankle. This ankle protector effectively relieves pain caused by pressure and rubbing from footwear on the medial and lateral malleolus. Placed underneath the sock, this protector stays firmly in place throughout any sporting activity.