This is a AmeriGlo Sight known as the I-Dot, model GL-102.
A quality set of night sights is a must if you plan on using a handgun for home defense and personal protection. Being able to aim in low-light conditions is an invaluable benefit made easy with the AmeriGlo I-Dot Tritium night sights for Glock handguns. These handgun sights are made from steel and feature a green tritium insert on the front sight post with a white photoluminescent outline for visibility during the day. The rear sight has only a single tritium lamp in the center that helps bring your eye to the front sight post for fast target acquisition. The I-Dot sight arrangement was designed with close quarters and speed in mind for those split-second moments where you don't have the time to line up a traditional three-dot sight. Just place the front dot on your target and squeeze the trigger. These pistol sights are easy to install and are a massive upgrade from your standard Glock sights. The AmeriGlo Tritium I-Dot sights are a great option for using your pistol day or night.
Features:
Green tritium with white outline .140 wide front;Green tritium w/no outline .180 wide rear