I bought a Tech Sight and put it on a beautiful 10/22-22 rifle. Frankly, I didn't like them at all and thought they ruined the slick lines of the rifle. I removed them and sold the set.
The Tech Sights found favor with the Appleseed shooters but for the life of me, I can't see how they belong on that rifle! It looks like someone hit them and they swelled up! I also had a heck of a time adjusting the rear elevation.
I replaced the Tech Sights with the same Williams sights as posted earlier. They are very simple, look great and work fine. Cost is about $39 at Midway.