The G26 and 27 haven't any rail for front outside mounting. I installed the the Lasermax guide rod sight on my G27 a couple of years ago. It installs internally by replacing the original guide rod in a matter of a few minutes. My gun has night sights, but in the dark you'll never get to line them up to shoot. It turns on and off easily and testing it in low light, in my case, hit within 4, or 5 inches at 25 yards. You have to learn to keep your hand steady though, which will take practice. Also, since it is internal there is no need for a special holster. Some say they're useless, but it's there if I ever need it. The drawback is it's price. This time of year sales are run and I got mine from OpticsPlanet at the cheapest price.