Under Moments Womens Spaghetti Strap Sports Bra Top (Blk,M,Pack of 2) Sexy, flattering, and comfortable with single straps Microfiber allow passage of moisture vapor, leaving the wearer dry and comfortable. Perfect for any athletic activity or just lounging around. Sizing Guide: S(34.5"-35.5") M(36.5"-38") L(39.5"-41") Microfiber: 85% Polymide (NYLON) and 15% Spandex (LYCRA)