?

I’ve had the dove tail version for a few years now and they are great rings. Never had any problems. With all that adjustability it’s still not easy to know you are perfectly parallel with the barrel. 
When you adjust windage to your optical centre how do you know if you should move the back of the scope or the front or both?
I bought them for my photon Yukon night vision. I couldn’t even zero it with the ajustment in the unit. 

I have to say I’m not as obsessed with having the scope optically centred now. If you have a scope that gives you a good amount of vertical adjustment and you optical centre it you can’t use that potential anymore. Why have it if you can only use half of it?

I now use my adjustable rings to make sure I can dial the turrets to any range I may want to shoot. 
Michael
 
You can order directly from Michael website, it's cheaper than the price he has on eBay - takes about a week to get here (TX) from UK. I ordered a few times with no hiccup, the first item will cost you 9 pounds for shipping, add a 2nd item will add 2 more pounds...wait until you need to order more one than if you want save a few bucks. SportMatch adjustable rings are second to none, beautiful finish and rock solid.

https://www.tawnadoairguns.com/