Well made - looks & feels great - Hogue Monogrip Rubber Handgun Grips Ruger Ruger Security Six Handgun Grip 87000

This is a really nice grip and it fits a Security Six with serial # starting 161. I had to shave off a tiny strip against the exposed frame with a razor blade, but this is sometimes necessary to adjust for minor frame variations. If your gun has a roll pin, it can be easily removed with a punch or nail set.
This a nice grip for stainless guns, as it doesn't cover the back frame and the black/stainless contrast looks nice. For a blue gun I'd use a grip that covers the entire grip frame (no exposed metal), like Pachmeyer (PK3175). On blue guns the exposed grip frame can rust from perspiration and skin oil if you don't clean/oil it after every use. The rubber and finger grooves feel good and provide a solid grip.