This is a combo set of UTG flip-to-side magnifier and UTG red/green T-dot sight. The flip to side magnifier has a quick detach mount and both optics will to fit a 20mm picatinny/weaver style rail, the center height of both is 40mm from the base to the center of the optic so that they are in perfect alignment when used together. With this pair you get a full field of view and crisp clear dot when looking through the magnifier.*Note: Does not include the mounting rail shown in pictures, this rail is for display purposes only. Leapers Red Dot Scope Includes flip open lens covers! Detail Information: Great Field of View and Unlimited Eye Relief Clear and Sharp 4.0 MOA T-Dot Sight No-Reflection High Tech Emerald Coatings Red or Green Dot Adapts to Any Environmental Background Optimal Height Design to Co-witness with Iron Sights Includes Both High Profile Cantilever Mount & Low Profile Vertical Mount with Innovative Quick Detach Mounting Deck to Use on Any Picatinny Rail Patterned Illumination Rheostat with Variable Brightness Levels Offers Stealthy and Infinitely Fine Adjustment Aim and Instant Lock On Target to Enhance Shooting Accuracy and Performance Most Versatile Dot Sight for Wide Range of Pistols, Shotguns & Rifles Leapers 3x Flip-to-Side Magnifier Detail Information: Broadband Multi-coated Lens to Provide Crystal Clear 3X Image Extremely Wide Field of View - 30% Bigger to Comparable Models from Other Brands Adjustable Eyepiece for Easy Dioptric Correction Precision Machining and Anodizing for Maximum Strength and Wear Resistance Innovative Flip-to-Side Mechanism for Quick Transition between 1X and 3X Image Patent Pending Quick-detach Lever Lock Mounting Base Optimum Height/Offset for Different Applications Completely Sealed and Nitrogen Filled for Fog/Weather Proof