The Drytex hinged knee suppoprt is a Neoprene alternative constructed of a unique nylon core and polyester Lycrar fabric that allows for improved airflow * Provides compression and support yet allows for breathability ideal in warm weather climates * Designed for mild to moderate medial lateral stability * Measurements taken 6 above mid-patella knee joint line and 6 below mid-patella circumference * Extra Small fits: Thigh: 13 - 15.5 (33 - 39 cm); Knee center: 12 - 13 (30.5 - 33 cm); Calf: 10 - 12 (25.5 - 30.5 cm) *