Once you have used a click lock you will never go back. I used this to secure a 2” diagonal to a CPC025 the tread is for large sct telescopes about 3.25 inches. Direct fit to rear of scope. Perfect fit to diagonal. Just slide the click lock to rotate diagonal to change viewing angle. A tad expensive but really good quality item very solid.

The click lock series are useful and well-made accessories but kinda overpriced.
Still I have something like 300£ attached to it (diagonal + eyepiece), in a very secure manner, with no problem of getting stuck (unlike the Celestron kit...)

Unlock/rotate/re-lock your star diagonal is now done with 1 hand, even with frozen fingers.
I consider this item as an insurance, any eyepiece/stardiagonal falling on concrete floor will end up costing me a lot more money.

I have attached this click lock adapter to my 12" SCT but as yet I am still waiting to use it. It will I hope solve the issue of the diagonal getting stuck on my SCT .

Great product, works very well but a bit overpriced.