What kind of swimsuit is this?

[SwimAddict71488]

I had been going through images on Google for the past several months trying to get ideas on getting a swimsuit made and came across the image below. I'm not sure what kind of suit this is but it's definitely the most perfect seat on a swimsuit I have seen so far. It could be a rio/ 3/4 back but I like that it's not to triangular in shape. It seems that suits like this were more common in the 80s (apparently when this photo was taken). Any ideas as to what kind of suit it is?

https://goo.gl/images/WMJV5c