Baader Planetarium (TCR) Hardened Steel T-2 ChangeRing (2456320)

Baader quickchange is excellent

I’m a fan of the Baader quick-change system. It’s ingenious, well made and makes the optical train very flexible. The only thing to watch for is if you’re using the system for eyeball optical accessories as opposed to AP, that steel dovetail ring’s clear aperture is 37mm so if you use it to attach a 2-inch eyepiece holder for visual use you might have issues with eyepieces tha have larger field stops.