This is one of those multi-purpose kitchen tools used years ago. One purpose is for opening jars. Constructed like vise-grips, the user “cranks” the grippers over the lid and locks the handle in place for a tight fit. At the end of the tool is a pick for breaking a seal or lifting paper lids out of the milk bottles. At the other end is another devise for popping the seal on pickle-like jars, or whatever other use one can think of.
If you collect innovative kitchen tools of yesteryear, this is a good one to have.