High quality silicone We recommend you to choose a size up;Normal and Double thickness available,please refer to our size chart;*Please according the effect you want to arrive for choosing the right proper size with your own breast's size. IF YOU ARE OVER DD size, MAYBE THIS KIND of invisible bra is NOT FIT YOU. Reusable and Easy to Apply. Attach directly to the skin, great to use with strapless and low-cut outfits and dresses Do not recommend for hot temperatures, because sweat may make it slip down-Do not use moisturizers, perfumes, powders or other skin care products prior to use, as this will reduce the effect of the adhesiveOpen Stars