manufacturers Part Number: SB03BK-XXL * EVS" innovative shoulder support system. New improved fit that increases comfort and stays in place on shoulder Increased shoulder stabilization & supportNew adjustable arm closure design eliminates underarm chaffing: fits arms of all sizesUniversal no snag design fits left and right sidesBreathable, 3mm perforated, Velcro compatible, neoprene construction * SIZING:SHOULDER BRACE SIZE BY MEASURING IN INCHES (Around the chest, under the arms)+ Small 30-36 inchesMedium 36-40 inchesLarge 40-44 inchesX-Large 44-48 inches