Tech sights have a peep rear, which is more instinctual and faster to aim, and the rear sight is mounted on the back of the receiver, extending the sight radius (distance between sights) which makes it easier to aim. The farther apart the sights are, the more obvious small misalignments become. I believe the company is Tech Sights. There are other options, but the real deal Techs seem to be a pretty sure bet on a great product.