Feature A Flexible Reticle Options: Six Patterns Include 3 MOA Dot, 38 MOA Circle, 46 MOA Crosshair w/ 1 MOA Audible Click Adjustment A Clear Distortion-Free Clarity: Aspheric Lens Minimizes Aberration and Eliminates Image Distortion for Natural and Sharp Target View A Convenient Side-Loading Battery: Replace Without Removing Sight or Losing Zero with Motion Sensor Auto Power Saving Support A Rugged Titanium Construction: Withstands 1000G Shockproof and IPX7 Waterproof Rating for Stable Performance in Harsh Conditions A Broad Platform Compatibility: MOJ Footprint Compatible w/ the RMR Standard Fits GlockA(R) 17/19 MOS and WaltherA(R) PDP Platforms Specification See our Terminology Guide for detailed explanations of each specification. Magnification: N/A Window Lens Size: 19x28 mm / 0.75x1.1 in Parallax: Free (