The new 517.A65 has been developed to optimize the functionality of the HWS. The buttons have been moved from the back to the left side for instant access, allowing a magnifier or a back up iron sight to fit closely to the HWS body. This new button position allows the user to operate the HWS function switches easier than ever before. Additionally, a portion of the front base has been raised to allow the sight to fit over standard hand guards found on many M-4 or M-16 style weapons Buttons on left side to work specifically with magnifiers AA Battery model (supports Lithium or Alkaline) Standard A65 image (65 MOA ring/1 MOA dot reticle) Interfaces to 1" Picatinny (MIL-STD-1913) rail Operation Optics: Transmission holography - parallax free Magnification: 1x Eye Relief: Unlimited Length/Width/Height: 5.70"x2.1"x2.8" (133x49x71 mm) Weight: Temperature: -40 to 150 F (using AA lithiums); -20 to 140 F (AA Alkaline) Waterproof: Submersible to 10 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: 1" Picatinny (MIL-STD-1913) rail Return to Zero: Repeatable to 1 MOA after re-mounting Heads-Up-Display Window 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 Electrical Brightness Adjustment Range: 146,000:1 brightest to lowest Function Button Location: Left side near the rear of sight Power Source: 2x 1.5V AA batteries (supports lithium, alkaline, or rechargeable) Battery Life: 1,000 continuous hours (lithium) at nominal setting 12; 600 continuous with AA alkaline Brightness Settings: 20 settings with scrolling feature Auto Battery Check Indicator: Flashing reticle upon start-up Auto Shut-down: At 8 hrs- programmable to 4 hrs Raised 7mm base