RX Fully Multi-Coated Optics increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces; HD (High Density) extra-low dispersion glass delivers impressive resolution and color fidelity, resulting in High Definition images; O-ring seals prevent moisture, dust and debris from penetrating the monocular for reliable performance in all environments; Argon gas purging prevents internal fogging over a wide range of temperatures; Ultra-hard, scratch-resistant ArmorTek coating protects exterior lenses from scratches, oil and dirt; Rubber Armor provides a secure, non-slip grip, and durable external protection; Versatile, multi-position utility clip allows for multiple attachment points and quick attachment to pocket edges; Ranging Reticle