I believe that is a tool used by A/C techs to open and close service valves, but of course many tools can be used for things other than their intended purpose. Good find.
I am going to have to put that on my Father's Day wish list.I've got a Gearwrench tap and die set with a ratcheting tap handle. Used it yesterday. Operates very smooth and makes tapping deep holes much easier. Love it.