Blackbough Swim Flo Mini Tube Dress | Wonderland. XS. Consider this your new summer staple. The Flo Tube dress puts a tasteful spin on the classic strapless dress. This structured, corset style dress is designed with an adjustable lace-up back. Wear it for lunch on a hot day or pair it with heels for a night out. 96% Polyester / 4% Spandex Criss-cross tie back for a custom fit