★RACERBACK: Anti-slipping comfortable wide shoulder straps and racerback style is a very fashionable design. ★79% Polyamide, 21% Elastane ★ADJUSTABLE EXTENSION STRAP: It's wide, one-piece under-bust elastic strap with adjustable extender for maximum comfort that effectively prevents the chest from expanding outwards and provides the chest region with excellent support during exercise. ★HIGH QUALITY FABRIC: 79% Nylon, 21% Spandex. The fabric is super elastic but never become baggy or out of shape. It's soft, breathable, easy to absorb sweat, and quick dry. ★FINE WORKMANSHIP: Seamless stitching, the clothes hem, and rim are great sewn, very sturdy, and durable as you can see.