Vortex 15x56 Diamondback HD Binoculars. The Vortex 15x56 Diamondback HD Binoculars are engineered for superior long-range and low-light performance, ideal for open, expansive terrain. Featuring oversized 56mm extra-low dispersion (ED) high-definition (HD) lenses, dielectric-coated and phase-corrected roof prisms, and proprietary multicoatings, these binoculars deliver exceptionally bright, crisp, and true-color images across the entire field of view with minimal distortion or color fringing. The ArmorTek exterior lens coating repels water, oil, and dirt to maintain optical clarity and prevent scratches. The lightweight magnesium alloy chassis, wrapped in protective rubber armor, offers a slip-resistant grip and excellent durability. Ergonomic enhancements, such as raised palm pads and thumb indents, ensure stable, comfortable handling during extended observation sessions. Argon-filled and O-ring sealed, the binoculars are fully waterproof and fog-proof, ensuring reliable performance in extreme environments. Given their powerful 15x magnification and 56mm objectives, Vortex recommends tripod mounting to eliminate hand shake and arm fatigue; a Uni-Daptor tripod adapter is included. A GlassPak harness system distributes weight evenly across the shoulders for comfortable all-day carry, while the included case provides added protection. Optical Performance includes 15x magnification for detailed distant observation, large 56mm objective lenses for bright, clear images, roof prism design for compact durability, dielectric and phase-correcting coatings for enhanced color fidelity and contrast, ED HD glass to minimize chromatic aberrations and improve sharpness, fully multicoated optics to boost light transmission, ArmorTek coatings to protect against scratches, oils, and debris, wide 65.4° apparent angle of view to reduce image vibration effects, and 230 ft. field of view at 1000 yards. Use & Handling features a short bridge design for stability, large textured focus wheel for easy adjustments, interpupillary distance 59–76mm, twist-up soft rubber eyecups for comfort with or without glasses, 15.6mm eye relief to reduce eyestrain, and 3.7mm exit pupil. Construction Details include a magnesium alloy body that is lightweight yet rugged, rubber armor for secure grip, waterproof and fog-proof design with argon gas and O-ring seals, slim Uni-Daptor tripod adapter, GlassPak harness and case for comfortable field carry, and tethered lens caps with Rainguard to protect lenses. MPN: DB-218 UPC: 875874007420