Rigid protection: Sturdy design constructed of an extra-strong polymer plastic shell and anatomically shaped uprights reinforce protection and support on both sides of your foot and ankle and facilitates a better fit.. Compression and comfort: Integrated pump mechanism easily inflates and deflates the pneumatic, soft foam/nylon liner for adjustable comfort and support.. Safe ambulation: Lightweight materials, rocker sole, durable tread pattern and inner/outer foam cushioning help absorb shock upon heel strike and promote a natural gait for a safe walking solution.. Hand washable. Large fits those who wear men's shoes, size 10½ – 12½, or women's shoes, size 11½ – 13½..