Made of high-quality sponge. Soft and durable. Pretty breathable comfortable summer wearing, the inserts are thin, they are pretty breathable, even when sweating a lot, they don't interfere with the moisture-wicking properties of your sports bras. Bra cups don't slip at all, move around, or stick out of your bras even when exercising pretty hard. These inserts are very lightweight compared to the silicone pads but also have enough weight to them that they don't move around. Perfect for your sports bra, yoga bra, bikini top, swimsuit, nursing bra. Also applies to evening gowns, wedding dresses, sweaters & casual wear, and just about any top that could use a droplets shaped insert. Whether hand or machine wash, no delamination or deformation occurs. A great natural way to give your bust a boost. Make you more beautiful and confident. Specification: Size: Approx. 15x11.5x3.7cm/5.90x4.53x1.46inch Material: Sponge Package Includes: 2x Bra Sponge Pads