NGC 2261

This is an old Meade reducer for Schmidt-Cassegrain telescopes, designed for cameras with small sensors. It was probably released about 10 years ago.

Interesting, does it really increase the light-gathering power by 3.3 times?

Indeed, from f/10 to f/3.3. It becomes a hyperstar at its minimum settings. However, it's far from perfect; there are always artifacts around the stars at the edges.

Wow! You can crop the edges, but with such a focal length, small targets like planetary nebulae or globular clusters become hard to capture. :) Any idea how to get my hands on something like that?

It depends on the planetary nebulae. For example, Star.Hunter captured the Ring Nebula with a C8 and a Meade f/3.3 reducer – https://star-hunter.ru/en/tumannost-m57-kolco-7-maya-2016-goda-0220/
You should keep an eye on the classifieds section on Astroforum; that’s how I bought mine. eBay might also be an option, but not under current conditions…

I checked, but according to his words, he achieved a reduction coefficient of 0.4 by adjusting the rings, which is quite sufficient for small objects.
I regularly browse the second-hand market, but haven't come across anything similar yet :(
Thank you for the information, good luck, and more great works of the night sky!

I think I saw it for sale at a flea market last year...
Thank you! You too!

P.S. If you happen to come across it in your field of view, please let me know. I can leave my phone number for contact: 8 913 850 4799, Alexey, city of Tomsk. On the forum under the same username.

Certainly!