Designed as an ideal optic for wide-view astronomical or long-range terrestrial observation, the Barska 20x80 WP Cosmos Astronomical Binoculars feature multicoated optics that reduce reflection and increase light transmission through the entire optical system, and traditional Porro prisms that provide a rich depth of view and high-contrast to draw you into an immersive viewing experience. To help offset the weight of the large objectives, Barska manufactured the chassis out of a durable aluminum alloy with a textured armor to help protect it from bumps and impacts while offering a slip-resistant grip. Due to the binoculars' large objectives and long optical tubes, a center stabilizer bar has been pre-installed with a built-in 1/4"-20 tripod adapter to mount the instrument. To handle a wide range of environments, the optical tubes are nitrogen-filled and O-ring sealed.