Jerry, I've been trying to remember where I got it - but can't. It's really made for larger sized exposed/external retainer or circlip rings so it may have come from an auto mechanic friend (who was also formerly a HVAC system installer for Trane). I earlier had mentioned it to another List member who said he has a similar tool made by a German company by the name HAZET. Mine looks like it was not expensive. It has a blackened finish, perhaps from heat treating, but it has no stampings on it at all. There is just printed directly onto the vinyl grips on the handles the wording "for external retainer rings" along with a simple illustration of a split / open circle (representing the typical part). I'm going to check if perhaps Snap-on has one or even a set in different sizes. Now those would definitely be the ones to go after... (I love Snap-on).
Bob Hanson, Albuquerque, New Mexico, USA