Mystery Adaptor 2" EP to 49mm external thread

[Stub Mandrel]

Not sure where to post this but...

With my SW 130P-DS I got several adaptors, including a number of adaptors for 2" and 1.25" eyepieces.

I also got a tube, just over 2" (50mm) long. One end is clearly for a 2" eyepiece, with two knurled fixing screws, the other is internally threaded at about 49mm. I thought it might be to adapt a smaller 1.25" SW focuser to 2" EPs, but it's too big a thread, and it's too small to screw on the end of the 130P-DS focuser, which takes an externally threaded adaptor anyway (I got a spare one with the scope).

My guess is it fits the 49mm external threaded focuser of some scope, somewhere, but which one? Any ideas what it might fit?

 

 

 

[Marci]

Sounds like a 2” visual back adapter for an SCT scope? Or a 2” Eye piece to M48 threaded filter wheel adapter...

[Stub Mandrel]

14 minutes ago, Marci said:

Sounds like a 2” visual back adapter for an SCT scope? Or a 2” Eye piece to M48 threaded filter wheel adapter...

The thread ID is about 47.8 mm so I doubt it's M48, it must be M49.

[D4N]

That is an odd size, the thread on my 300P focuser tube is M54 so you can rule that out