A fabulous bra, popular with ladies of all sizes. The best selling bra that we stock. The anti-bounce design works! Jo and Heather both wear the 518 and would not go back to the traditional style. It is multi seamed and has an aggressive hold and we would not recommend it if you are prone to chaffing, although all seams are now flat locked. It is an art form just to get it on and off, but well worth the effort. A good choice to wear under triathlon clothes as it is a single layer of fabric and dries quickly