Sidearms & Scatterguns Rmr on glock

Depends, you have 3 options. Rmr cut slide makes it easy but for a g20 good luck finding a good one. The rmr sits lowest this way and is most secure. The second option is a rmr mount that fits the rear dovetail and replaces the rear sight. Rmr sits higher and you do not have a back up rear site, but if you practice you can line up the front site with the center of the rmr. The last option is the new tiny trijicon that fits in the rear sight.