Both of our Diana and Maya swim dresses attach to any of our swim bottoms with an adjustable secure button tab. This is to prevent the swim dress from floating/riding up in the water and exposing your torso. Our Lula, Mira, Serena and Taali swim dresses are full one-piece bodysuit swim dresses and do not need to attach to the swim bottoms as there is no risk of exposure if the swim dress were to lift. You may notice a button on your swim bottoms, with nothing to attach it to on the Lula, Mira, Serena and Taali swim dresses. This is because all of our swim bottoms are produced with a button in case you wish to pair it with a Diana or Maya swim dress.