A lighter, smaller version of the Model 552, the Model 551 offers the same durability and function, but in a more compact unit. At 4 inches in length, this sight takes up less valuable rail space, leaving more room for a rear iron sight or NV mount.
- N Battery
- 65 MOA circle with 1 MOA aiming dot reticle pattern
- Compatible with Gen I-IV Night Vision Systems (tandem operation)
- Includes rugged aluminum hood assembly and knobbed tool-less mounting bolt
- Interfaces to standard 1" Weaver dovetail / Picatinny rail
Operation
- Optics: Transmission holography - 100% parallax free
- Magnification: 1x
- Eye Relief: Unlimited
- Length/Width/Height: 4"x1.8"x2.25" (102x49x60 mm)
- Weight: 8.8 oz (250 grams)
- Temperature: -20 to 140 F
- Waterproof: Submersible to 33 ft depth
- Sealing: Fogproof internal optics
- Color/Finish: Non reflective black with hard coat finish
- Adjustment (per click): 0.5 MOA (1/2" at 100 yds)
- Adjustment Range: +/- 40 MOA travel
- Mount: Picatinny (MIL-STD-1913) rail
- Return to Zero: Repeatable to 2 MOA after re-mounting
- Optical Surfaces: Anti-glare coating
- Window Dimensions: 1.20" x 0.85" (30 x 23mm)
- Front Window Material: 1/8" solid glass
- Rear Window Material: Shatter resistant laminate (3/16" thick)
- Field of View (100 yds): 30 yds (28m) at a 4" eye relief
- Standard Reticle: 65MOA circle with quadrant ticks with 1 MOA aiming dot
- Brightness Adjustment Range: 110,000:1 brightest to lowest
- Night Vision Brightness Range: 1000:1 with NV switch engaged
- Power Source: 2x N type 1.5V alkaline batteries (3.0V)
- Battery Life: 200 continuous hours at nominal setting 12
- Brightness Settings: 30 settings with scrolling feature (10 settings for NV use)
- Auto Battery Check Indicator: Flashing reticle upon start-up
- Auto Shut-down: At 8 hrs- programmable to 4 hrs
