First Look: Glock Gen4 MOS Pistol

Not only is Glock is expanding its line of Gen4 MOS pistols, but it's also expanding on a larger trend of using optic sights with personal protection pistols. MOS stands for "Modular Optic System," which simplifies the mounting process and eliminates the need for costly custom machining of the slide. Here's a quick look. You can find out more at us.glock.com.