Sports Jock are undoubtbly one of the best sports bras on the market, they offer excellent support, comfort and reliability. The exclusive "Powerband" construction with keyhole racer back provides the ultimate in comfort and support, manufactured from DuPont Supplex outer fabric, for softness and shape and Coolmax inner lining to keep you cool and dry, can be worn as outer or undergarment "Super Sport Bra" is designed for cup sizes C,D,DD and F for smaller cup sizes go too "Action Sport Bra" The only difference between SJ1652 and the SJ652 is the fabric/price. A really good all round top excellent for running, or wearing in the gym.