Is this a Rini 4x Barlow?

I have a piece of equipment I can't identify. Heavy 2" (probably Barlow) . labelled Rini 4x. It appears to be finely threaded on one end. Help1

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Have you looked thru it at an object that is relatively close (like your keys on a table 6 inches to a foot away). If it is a 4x Barlow, the keys will look significantly smaller and further away. Can you then get an image of the keys (or a ruler) with and without the RINI 4x interposed in the path between the camera and the keys/ruler. Then take a photos of the threaded end with a ruler in the photo and post these photos here or on Cloudy Nights site.

Hey Optics gurus, any further ideas on how to make this ID of a 4x Barlow more certain ?