AmeriGlo GL191: This is a XL tall set of sights to fit a Glock that has a suppressor on it. This raises the entire sight picture so it views over the suppressor. This is the I-Dot (inline dots) style with only 1 dot on the front and one dot on the rear sight. This simplifies sight alignment and allows for quick target acquisition. The front sight has a green tritium dot surrounded by a white outline and the rear sight has a single green tritium dot. NOTE: Will not fit Glock 42, 43