Lace up brace helps prevent &, support ankle sprains and/or injuries. Outer & inner 3D mesh layers for softer fit & more breathability. Plastic insers in sides give added support & protection. Cut outs around the ankle bone allow for brace to be worn comfortably inside riding boot. Sizes S = EU 38-41, US 6-8 M = EU 41-44, US 8-10 L = EU 44-46, US 10-12 XL = EU 46-49, US 12-14