Vortex Viper HS 4-16x50 Riflescope Vortex Viper HS riflescopes offer hunters and shooters an array of features sure to be well received. The advanced optical system, highlighted with a 4x zoom range, provides magnification versatility. A forgiving eye box with increased eye relief gets shooters on target quickly and easily. Built on an ultra-strong 30mm one-piece machined aluminum tube, the Viper HS delivers increased windage and elevation travel for optimal adjustment. Optical Features XD Lens Elements Extra-low dispersion (XD) glass increases resolution and color fidelity, resulting in crisp, sharp images. XR Lens Coatings Vortex proprietary XR fully multi-coated lens coatings increase light transmission for maximum brightness. Construction Features 30 mm Tube Provides greater strength and wider adjustment lattitude. One-Piece Tube Maximizes alignment for improved accuracy and optimum visual performance as well as strength and waterproofness. Aircraft-Grade Aluminum Construction from a solid block of aircraft-grade aluminum delivers increased strength and rigidity. Waterproof O-ring seals prevent moisture, dust, and debris from getting inside the tube for reliable performance in all environments. Fogproof Filled with argon gas to inhibit internal fogging over a wide range of temperatures. Shockproof Lenses are locked in place, fore and aft, with machined locking rings to remain in perfect alignment and withstand recoil and impact. Hard Anodized Finish Hard-coat anodization is durable; the low-glare matte helps camouflage the shooter’s position. ArmorTek Ultra-hard, scratch-resistant coating protects exterior lenses from scratches, oil and dirt. Convenience Features Capped Turrets Protect from accidental movement and impact.