I found this poor to use, as could not get tight fit (when it did hard to undo) and would not move to allow angle adjustments and made squeaking noise. Ended up getting a click lock and much better

Had to return this not because of quality - just didn't fit my diaganol which was a "Williams Optics clone" -adaptor is 48mm whilst my diaganol is 45mm ?? - not possible to go from 48 to 45 easily - so other route taken.
Service good as usual

I was very pleased to find this item which appears to be very well engineered and a good match for the Williams Diagonal purchased at the same time. I've only used it for a couple of sessions so far and have found it difficult to get a tight fit quickly to the back of my Meade SCT. I have found that it slips round quite easily and requires a bit more effort to ensure security. When slewing the scope you obviously need to keep adjusting this fitting to get the diagonal in the right position. I feel sure that I will get the knack and that this will improve with further use. The lock ring space between scope and diagonal is also fairly restricted which with fat fingers or gloves impedes access somewhat

Purchased one of these 3yrs ago,. First use I noticed the threads binding but only used it a couple of times due to ill health and work commitments. Came tonise it again recently and it’s completely seized. I mean seized solid somthat not even a vice and a strap wrench can shift it. FLO unable / unwilling to assist which is a shame as Age I’d item doesn’t equate to usability or fitness for purpose. I now have to purchase another and find something to lubricate the threads that won’t migrate. Shame as I have no option other than to throw away a perfectly excellent diagonal.

I bought this for connecting my sct to a new williams optics star diagonal. The first one which was delivered was faulty as the moving part between thread and body didnt move for adjustment of the position. The FLO team were excellent in sending out a new one asap whilst also sending me the postage for returning my fault one. Top class! An essential adapter for sct to 2" diagonal