XD Lens Elements: Extra-low dispersion (XD) glass increases resolution and color fidelity, resulting in crisp, sharp images; Fully Multi Coated Lenses: Anti-reflective coatings on all air-to-glass surfaces provide increased light transmission for greater clarity and low-light performance; First Focal Plane: Scale of reticle remains in proportion to the zoomed image. Constant subtensions allow accurate holdover and ranging at all magnifications; Glass-Etched Reticle: Allows for intricate reticle design. Protected between two layers of glass for optimum durability and reliability; Nitrogen Gas Purged: Gas purged and o-ring sealed for fogproof and waterproof performance in all conditions; Aircraft-Grade Aluminum: Constructed from a solid block of aircraft-grade aluminum for strength and rigidity; Waterproof: O-ring seals prevent moisture, dust and debris from penetrating the riflescope for reliable performance in all environments; Hard Anodized Finish: Highly durable low-glare matte finish helps camouflage the shooter's position; Precision-Glide Erector System: Uses premium components in the zoom lens mechanism to ensure smooth magnification changes under the harshest conditions; Precision-force Spring System: Uses premium components in the erector-spring system to ensure maximum repeatability and ease of adjustment