Performance Calf Sleeves Benefits Performance is the key to success, especially for athletes. Your body needs proper circulation to keep up with your active lifestyle. Get Back in the Game with the CS6 Performance Calf Sleeves The OS1st CS6 Performance Calf Sleeves provide medical grade orthopedic support. Our patent pending Compression Zone Technology provides pain relief and preventative support. CS6 Performance Calf Sleeves provide athletes with relief from calf pain and injury. Find prevention and relief from muscle cramps, venous insufficiency, Achilles tendinitis, and shin splints.