Maybe I missed something here along the way, but, from what I've read, it is only the XTR rings that have the variable inserts? Which have to mount on a pic rail. Not aware of the std Signature rings having those inserts available, and I'm pretty sure the XTR ones won't work in std ones. I asked Burris if they had any plans to make a lower XTR height than current and very carefully explained my issue, and they had no solution.