Re: What is this?

Here is the description of the bottom piece by Williams Optics, now discontinued. No price listed for this now, but might be worth $25-35.

"Expand the accessory capabilities of your ZenithStar 66 with this practical and inexpensive SCT adapter/extender!
Will fit any telescope that has an SCT 2" back: if you have a standard 2" standard diagonal for your refractor, you won't need a new one for your SCT!
SCT Adapter
• Allows connection of 2" accessories, such as photo adapters or 1.25" diagonals, to ZS 66 and other 2" SCT-threaded telescopes."

The upper piece is an extension for that, with a compression fit 1.25" adapter to allow you to use either 2" or 1.25" eyepieces. Sometimes you need this extension to achieve focus. Not sure of the exact cost, but $45-50 I think. Might bring another $30-35.

These prices are not necessarily right, but are probably about the value today.
Floyd

I had each of those parts. They came with a William Optics Zenithstar 66 refractor telescope I used to own. The Zenithstar is a 66mm refractor that used to be made by a company called William Optics.

I'm sure those adapters would be useful for other telescopes, but that's where I've seen them.

Not a problem, we all need help from time to time.

Floyd