they were a dovetail base ring...but they had little levers on the side that controlled the screws, instead of using an allen wrench... you could take it off if you wanted to and re install it with your hands... they were expensive tho when i bought them, like 125 a pair... i had another pair on my AR, with the scope i have still, but sold the rings with the rifle...

not even sure they still make them anymore, i thought they were cool as hell, and even after taking the scope off, the gun was only like 1-4 inches off, so it was easy to sight in again...

they were made by Leupold tho, so they might still be around somewhere...