Marvel Avengers.Arm sling with lightweight envelope and strap release clip designed for easy application and comfortable fit. RECOMMENDED FOR: Immobilization and support of the arm shoulder and elbow joints. Strap release clip aids in on/off application. Cotton/polyester envelope helps with a comfortable fit. Adjustable strap length aids in a proper fit. Universal design fits right or left arm. Size based on arm length: up to 11 .