This is a EOTech Magnifier known as the G33, model G33.STS.
The new G33.STS magnifier is shorter and lighter than previous models. The improved mount provides faster transitioning from 3X to 1X. The G33 offers tool free azimuth adjustment" a larger field-of-view and an adjustable diopter for improved" precise focusing.
Features:
Water resistant
Fog resistant internal optics
MIL-STD-1913 rail 1 Weaver;Fixed 3X magnification
