Features: 1. Three-dimensional stitching, fit the ankle; perforated fabric, comfortable and not stuffy. 2. Hook and loop closure. The length can be adjusted freely for winter ankles and foot treatments. 3. With elastic belt, safe comfortable to wear. 4. Magnetic Self-Heating, no battery, no electricity needed. 5. Perfect for relieve fatigue and pain of feet. Notice: 1. Actual color may be slightly different from the image due to different monitor and light effect. Specification: Material: Mercerized cotton composite, hook-and-loop, spandex, magnets Size: one size, adjustable Color: black