Long Sleeveless V Neck Mermaid Prom Dress with Sequins Bridelily Long Mermaid One Shoulder Sequins Open Back Formal Prom Dresses with S Sparkly V neck Sleeveless Mermaid Sequin Long Prom Dresses With Traili Elegant Lace Long Sleeves Open Back Mermaid Evening Dresses Long Fitted Mermaid Long Prom Dress Backless with Open Back #LN104. Shine at prom with this elegant mermaid style dress. In a classic black hue with a velvet floral pattern, it features a square neckline, sleeveless design, an open back, and a long skirt with a thigh high slit. Perfect for a sophisticated, standout prom look.