I second what WingedMelon reported. I have many Holosun optics, such as this 1, and have never had a problem with any of these. I'm truly selling my Trijicon RMR to receive One more 1. The 507 is on par, if not greater, than my DPP.Indeed! I want to acquire news and updates from Guns Worldwide. This tackle will not be bought or useful for promotion