Patented lacing system ensures superior support as laces start twice as tight and stay tighter longer. Constructed from triple-layer vinyl laminate material with internal spiral-wound stainless steel stays. Seamless arch guarantees improved fit and comfort, and full elastic back allows unrestricted blood flow to the Achilles'-tendon area. Knit tongue allows air flow. Fits right or left ankle, in wearer's current athletic shoe, and is guaranteed for 1 full year.Return/Size Chart for Ankle Lok: Return/USA Men’s: X-small 3–5, Small 6–7, Medium 8–10, Large 11–12, X-large 13–14 Return/USA Women’s: X-small 4–6, Small 7–9, Medium 10–11, Large 12–13, X-large 14–15