This is a tweeter pod for the Ciare CT250 tweeter. It is designed to be used with this swivel lamp hardware. https://grandbrass.com/1-8ips-male-threaded-x-1-8ips-female-threaded-knurled-swivel-polished-nickel/

Here are links to purchase the tweeters.

https://www.droppinhzcaraudio.com/collections/ciare/products/ciare-ct250-tweeter

https://www.parts-express.com/Ciare-CT250-1-Neodymium-Dome-Tweeter-Pair-293-100?quantity=1