- seamless - double preformed cups - wirefree - satin piping - adjustable straps - back hook and eye closures - machine wash - 85% polyamide, 15% elastane Perfect Microfiber Bra - the perfect companion for every day. The double preformed cups offer an ideal fit. Wide, lightly lined straps prevent cutting into the skin. Wirefree. Back hook and eye closures. A great t-shirt bra! Perfect for so many occasions. With SO PROPER - SO PROSPECTIVE label you can see that our garments are made partially or even completely sustainably.