Celestron’s SkyMaster Series of large aperture binoculars are a phenomenal value for high performance binoculars ideal for astronomical viewing or for terrestrial (land) use – especially over long distances. Each SkyMaster model features high quality BaK-4 prisms and multi-coated optics for enhanced contrast. Celestron has designed and engineered the larger SkyMaster models to meet the special demands of extended astronomical or terrestrial viewing sessions