Orion 9546 Resolux 15x70 Waterproof Astronomy Binoculars 15-power astronomical binoculars with a rugged housing provide high-resolution views with a pleasing flat-field Fully waterproof and nitrogen purged construction prevents lens fogging High-quality BAK-4 prisms and advanced multi-coatings on all optical surfaces provide maximum light throughput for bright views rich in contrast The high-power 15x70 Resolux binoculars have a nice 4.4-degree field of view for big views Attachment to a tripod with the included tripod adapter is recommended for extended use