From Fashion Forms, the Lift It Up Backless Strapless Plunge Bra features:
The Lift It Up Backless Strapless Plunge Bra is the answer to backless, strapless dressing while preserving a flattering breast shape and modesty
Silicone allows lift and coverage while being undetectable under clothing
Reusable if cared for properly by hand washing with mild soap and water, air drying and preserving adhesive with original protective plastic
Apply product to clean, dry skin before moisturizers, powders, deodorants, or perfumes and adjust as many times as needed without fear of the product loosing stickiness