The Popeil Brothers brought this one to market in the 50’s. The patent was filed by Samuel J. Popeil in 1949 and was granted in 1952.
The multicolor plastic holds the blade in three positions and a cotter pin holds the blade in place.
Look at the graphic for how you are supposed to hold the back of the Slice-a-way to stabilize it. Looks pretty dangerous to me.
Also on the box it says “No. 14” not sure if they made this in different sizes or this was the 14th Popeil item.
Here’s the original patent application: