Two were defective. - Holosun HS503BU Micro Red Dot Sight

I had two of these come with the front glass broken and optic not functioning. This tells me they have terrible quality control. It's really easy to look at the glass and see the front glass broken. If they were damaged in shipping with all of the packing around the optic, I'm guessing they won't hold up well on a firearm. Just garbage. Optics planet was awesome to deal with. Their customer service was 5 stars. I will keep buying from them.