HD Optical System delivers exceptional resolution, cut chromatic aberration and provide outstanding color fidelity, edge-to-edge sharpness and light transmission; Fully Multi-Coated increase light transmission with multiple -reflective coatings on all air-to-glass surfaces; Adjustable Eyecups twist up and down for comfortable viewing with or without eyeglasses; Helical Focus allows for fast and fine adjustments; Ultra-hard, scratch-resistant ArmorTek coating protects exterior lenses from scratches, oil and dirt; Waterproof, Shockproof and Fogproof; Rubber Armor provides a secure, non-slip grip, and durable external protection; Tripod Adaptable allowing use on a tripod or car window mount (Tripod adapter required); Rotating Tripod Ring allows rotation of the eyepiece to a sideways position, providing adjustable viewing angles; Built-in Sunshade reduces glare and shields the objective lens from raindrops and snow