Butler Jacket Name

What's the name of a suit without a butler? Is your real name

It was open, with a few inches between the two sides that would meet when closed.

Sorry, I can smell the details.

Here is the picture:

I believe the sleeveless jacket is called a cutway which is worn over a simple vest called a vest. The tailcoat has its own name and, according to Wikipedia, is a coat in which the front of the skirt is cut off, leaving only the back of the skirt, called the tailcoat.