Halter top navy long formal dress with open back

Size XS/S maxi formal open back dress. only worn two times. The straps and side of the dress have been taken in a bit by a seamstress to give a more fitted look. I think I initially got this from Lulus but when I had it fitted the tag is no longer visible. This dress was great for proms, winter formals, weddings and really any formal event. Dress has underlay and top layer.