HD Optical System delivers exceptional resolution, cuts chromatic aberration and provides outstanding color fidelity, edge-to-edge sharpness, and light transmission; Fully Multi-Coated Lenses provide increased light transmission for greater clarity and low-light performance ...HD Optical System delivers exceptional resolution, cuts chromatic aberration and provides outstanding color fidelity, edge-to-edge sharpness, and light transmission; Fully Multi-Coated Lenses provide increased light transmission for greater clarity and low-light performance; Rubber Armor provides a secure, non-slip grip, and durable external protection; Nitrogen gas purged and O-ring sealed for fogproof and waterproof performance; Tripod Adaptable - Allowing use on a tripod or car window mount. Arca-Swiss foot; Waterproof - Designed to withstand harsh weather conditions; Fogproof - Designed to withstand a wide range of temperatures; Shockproof - Designed to withstand impact