Orion 9543 Resolux 7x50 Waterproof Astronomy Binoculars These rugged 7x50 Orion Resolux astronomical binoculars have high-resolution, flat-field optics for sharp, detailed views of night sky wonders Fully waterproof and nitrogen purged binoculars prevent lens fogging, even in damp conditions Top-quality BAK-4 prisms and advanced multi-coatings on all optical surfaces yield maximum light throughput for optimal image brightness The moderate-power 7x50 Resolux with 7