Ameriglo

Ameriglo introduced CAP(Combative Applications Pistol) sights. These are designed by Officer Dave Spaulding and its core design seems to be comparable to  Heinie Straight 8 sights. Instead of a circle in the bottom, it has a flat line, and the tritium insert in the front sight is surrounded by square layer. There are three kinds available, and one of the models can be charged and glow in dark with flashlight.

EDIT: Earlier version of this post called the sights Spaulding sights, which is incorrect. It's called CAP sights. You can read more about this sight from here