The sleek, ergonomically designed Vortex Diamondback HD Binoculars are comfortable to hold for extended periods of glassing. An HD optical system improves resolution, and multiple anti-reflective coatings on all air-to-glass surfaces and multi-layer prism coatings enhance light transmission. A lightweight magnesium chassis provides extreme durability, and a rubber-armor exterior provides a secure hold and helps to absorb shock. Vortex binoculars are argon gas-purged and O-ring sealed for waterproof performance and to prevent internal fogging over a wide range of temperatures. A center focus wheel adjusts the focus of both binocular barrels at the same time, and twist-and-lock eyecups provide comfort with or without eyeglasses. Includes Glasspak binocular harness. Manufacturers lifetime warranty. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Binoculars.