It could be a cartridge demagnetizer. These were popular in the 90's but haven't seen them lately. That's my guess. BTW, if you don't have the manual, just throw away...
What is this?
Hi all, excuse my lack of knowledge here. I recently purchased a vintage turntable. It came with one of these. I know it fits a headshell. Other than that I have no idea what it is or how to utilize it? Any old school knowledge out there that can help identify? I don't know how to upload a photo here so I put it as my picture.