Ideal for amateur astronomers, the Sky Master Pro binoculars from Celestron have large 70mm objective lenses that are ideal for low light conditions or astronomical observation. They are both waterproof & nitrogen-purged, making them suitable for use in all & any weather conditions, & are rubber-armoured to protect from knocks & scratches. Built into the binoculars are a tripod adapter & RSR rail for attaching a red dot finderscope. With each surface multi-coated with Celestron's proprietary XLT coating technology, & Ba K-4 prisms within the binoculars, the Celestron Sky Master Pro 15x 70 Binoculars will produce crisp, high contrast images with outstanding resolution.