Made for comfort and performance using Dry Wear technology that wicks moisture away from your body. Contoured shoulder strap with a deep T-back for better fit and freedom of movement. Flexible design made exclusively for use with a Polar Heart Rate Monitor. Made of Poly/Lycra with a CoolMax and Lycra lining. Sizes: S (32 A, B, C / 34 A, B) M (34 B, C / 36 B, C), L (36 C, D / 38 C, D) XL (36 D, DD, 38 D, DD).