What is Neoprene Shoulder Support? A combination of theraputic heat & support promotes enhanced healing after shoulder injury & complaints such as arthritis & rotator cuff tendonitis. When can I use it? This bilateral support (can be worn on left or right shoulder) warms the shoulder while giving stability & joint flexibility to quicken the healing process. Made from soft neoprene, it can be worn all day for comfort against tendonitis, shoulder instability, shoulder dislocation & arthritis. What size is it? (Take the measurement from around the top of your arm) Small 28-33cm (11"-13") Medium 33-35cm (13"-14") Large 35-38cm (14"-15") X-Large 38-42cm (15"-17") Perfect for rehab following: Shoulder dislocation Rotator cuff tendonitis Shoulder instability