BERLEI Sport Bras have been engineered to be the perfect blend of function, fashion, comfort and support. BERLEI Sports Bras are the only bras to be tested, used and approved by the Australian Institute of Sport. They are the only sports bras proven to reduce breast bounce by up to 60%. The unique BERLEI Support Factor system has been created in conjunction with the AIS to help women find the right level of support for their chosen activity. SF2 bras are for medium impact sports, SF3 bras are for high impact activity, and SF4 bras are for extreme impact activity.