This brace best fits individuals whose size is in the middle of the size range. To achieve an optimal fit, we recommend ordering the next size up if your size is above the mid-point of the size range. Right or left shoulder versions available; Measure around the chest: Small: 35 - 39 inches; Medium: 39 - 43 inches; Large: 43 - 47 inches; X-Large: 47 - 51 inches. LP is recognized as the industry leader in the sports medicine category and in technical protective wear and has been well received by sports medical professionals. Success stories from athletes who have benefited from these innovations inspire us to keep creating high performance protective supports to meet our customers needs.