Better than i expected!
Pro's: Thumbscrews are a nice change to usual hex key fitting on a 20mm rail, I have these on my MP5 and because the midsection is hollow, i get to use my 4x28 SMK telescopic sight AND my ironsights!
Con's: The ring diameter isn't exactly 1", the interior ring padding that prevents damage makes the top half of both rings sit a little bit uneven, but they screw down nice and snug, so nothing major.
