Bamboo Rayon Bamboo is a biodegradable, naturally anti-microbial, anti-fungal and hypoallergenic fiber Compression 2" compression arch support provides foot fatigue relief by promoting circulation Length Knee or calf length Material 61% Bamboo rayon, 25% Rubber, 10% Polyester, 2% Nylon, 2% Spandex Small - EU 32-36 Medium - EU 37-40 Large - EU 41-43 X-Large - EU 44-47