These cards are sometimes called K or Cantilever depending on which brand of plastic template you buy. I prefer to think of them as flip cards because the cut panel from the inner flips into place.
My templates have minature perforations to create the score lines meaning you'll always get the inner and outer layers to match perfectly. Available as either square or circle templates they work best as a 5" sqr card. The files will come as 2 svgs and cost £1 each.
These spinner cards are great fun to decorate. They're hard to describe as the central panel looks square or circular when closed but as they open they twist to reveal the other side of an elongated circle or rectangle. I do have a decorate one on my SU blog if you want to see what I mean. The score lines have once again been created using a series of minature perforations.
Available as a circle or square centre the svg is sized to create a 5" square card and costs £1.00