Full Effect push-up design combines lightweight gel & air within padding to naturally enhance the bust, boosting you by up to 2 cup sizes*. Straps can be crossed over. 45% polyester, 43% polyamide, 12% elastane. Machine washable at 30°, preferably in a small mesh bag.*â2 cup sizesâ is a general indication based on information collected. Out of 123 women asked by & for WONDERBRA in the UK in 2010 (only A & B cups), 60% said that this bra increased their bust by 2 sizes.