Strap Back Detail Maxi Dress. The sexy cut out detail at the back adds a new twist to the classic black maxi, which is sure to become a wardrobe staple this summer. Just add sandals and a statement necklace and you will be beach bar ready in seconds! 95% Polyester, 5% Elastane. Scoop neck. Diamond shape open back with strap detail. Built in bra. Maxi length. Regular fitting. Model is 5'8 and wears a size S. Centre back length of garment is 143.5cm. And buy this Strap Back Detail Maxi Dress Now £28.00.