Four-way stretch material provides even, localized support, protection, and pain relief while allowing virtually full range of motion. Neoprene interface material retains body heat and increases circulation to help maintain flexibility. Includes a pocket for optional use of hot/cold gel pack. Completely reversible, fits right or left side. Measure around the chest at the level of the arm pit. Available Sizes: Small - Up to 40 Inches (102 CM), Medium - Up to 41 to 51 Inches (104 -127 CM), Large - 51 to 60 Inches (130 - 152 CM).