The Viper HD 12 x 50 features High-Density extra-low dispersion glass that delivers impressive resolution and color fidelity, resulting in High Definition images. XR fully multi-coated lenses increase light transmission for optimal brightness. Dielectric multi-layer prism coatings provide bright, clear, color-accurate images. ArmorTek protects exterior lenses from scratches, oil, and dirt. Argon gas purging with O-ring seals guarantees superior fog proof and waterproof performance. Phase-corrected prisms for sharp images and contrast. Rugged rubber armor provides a secure, non-slip grip. Includes locking diopter.