Primary Arms SLx The SLx 3x21mm Micro Magnifier Red Dot Sight Black. These Red Dot Sight Magnifiers from the inventors at Primary Arms feature a 3X magnifier for increased visibility in low-light and twilight conditions. With an integrated diopter the Primary Arms Compact 3X Red Dot Magnifier can switch between magnifications without missing a beat or becoming blurry and pixelated. Affordable and ergonomic the Primary Arms 3X Prism Red Dot Magnifier is the perfect solution for your newest rifle. Specifications for Primary Arms SLx 3x21mm Micro Magnifier Red Dot Sight: Manufacturer: Primary Arms Finish: Matte Magnification: 3 x Objective Lens Diameter: 21 mm Eye Relief: 1.9 in Weight: 9.1 oz Field of View Linear: 39.37 ft at 100 yds Optical Coating: Fully Multi-Coated Fabric/Material: Aluminum Color: Black Condition: New Water Resistance Level: Waterproof Mount Type: Picatinny Magnification Type: Fixed Attachment Type: Picatinny Features of Primary Arms SLx 3x21mm Micro Magnifier Red Dot Sight: 3x Magnification 21mm Objective lens diameter 7.0mm Exit pupil 5.3 ounces Compact design Package Contents: Primary Arms SLx 3x21mm Micro Magnifier Red Dot Sight Primary Arms SLx The SLx 3x21mm Micro Magnifier Red Dot Sight Black 510010