Red-carpet ready, this beautiful long satin mermaid prom dress is a PromGirl Exclusive. A sophisticated choice for prom, galas, and other formal events, this long mermaid prom dress features a plunging neckline and off-the-shoulder banded sleeves that offer a look of romance. The long satin formal dress has a banded waist that tops the long mermaid skirt that opens in a side slit before draping to the floor in tiers. A dramatic sweep train finishes the look of this gorgeous long satin mermaid prom dress that is surprisingly budget friendly at under $200.