The Prep Bible.
These two units fit different platforms. Read this as a line-vs-line breakdown, then pick the version cut for your own setup.
AmeriGlo Trooper GL-820 is a night sight set built for the Glock 20/21, using green tritium and a dovetail mounting setup. It's listed with a black color finish and an illuminated feature set, priced at $105.99.
Trijicon HD CA128Y is cut for the Colt 1911 with a Novak cut, also dovetail mounted. It comes with a yellow front sight and a green reticle color listed in the specs, plus both illuminated and shock proof features. The rear sight mounting location is called out specifically, and it's priced at $157.99.
Both are handgun night sights with dovetail mounting and illuminated tritium, but they differ in color callouts (black body with green tritium on the AmeriGlo versus yellow front with green reticle color on the Trijicon), in the shock proof feature listed only on the Trijicon, and in price.