What is this used for?

67Dart273 said
It was not built in the 20's, either. No such square drive existed then

There were square drives in the 20's,I have a tool box full of my dads tools from the 20's-30's.
This is a page from the 1923 Snap on catalog
https://collectingsnapon.com/2023/02/04/1923-catalog-a-2/