The Glock 19V is the newest evolution of the reliable Glock 19, looking similar to a Gen 5 but featuring internal redesigns, especially around the striker channel, to prevent illegal modifications (like "switches") while maintaining the familiar Gen 5 feel and holster compatibility, with key visual cues being the "V" marking on the frame/slide and a distinct slide backplate design. Internally, it has a larger striker and narrower striker channel, making parts non-interchangeable with standard Gen 5s, though trigger feel, grip, and shooting performance are nearly identical to a Gen 5, says Glock Store and other reviewers. 
Key Differences: Glock 19V vs. Standard Glock 19 (Gen 5)
Markings: The 19V has a "V" stamped on the frame and slide.
Slide Backplate: The V model has a unique, stepped contour on the rear slide plate, unlike the squared-off Gen 5 version.
Internal Design (Anti-Modification): The 19V has raised channels and a narrower firing pin channel in the slide, preventing the installation of illegal auto-sears ("switches").
Parts Compatibility: Due to internal design changes (like the striker and channel), parts are not interchangeable with standard Gen 5s.
Optics Cut (MOS): Early 19V models generally lack the MOS (Modular Optic System) cut, though future V Series variants might include it. 
Similarities: What Stays the Same?
External Feel: The grip, grip angle, and overall handling are virtually identical to a Gen 5.
Holster Fit: Standard Gen 5 holsters fit the 19V.
Trigger: The trigger pull (take-up, resistance, reset) feels the same as a Gen 5.
Features: Retains Gen 5 features like front/rear slide serrations, ambidextrous slide stop, and flared mag well.
Performance: Shooting experience, reliability, and magazine compatibility (with standard G19 mags) remain consistent.