10x30 center-focusing Waterproof Binoculars. BAK4 Prism. Nitrogen-filled to reduce fogging. Retractable eyecups. Molded rubber grips. 10 times magnification and a 30mm aperture. The included flotation strap keeps them from sinking. Powerful enough for most applications without being too large and heavy for transporting. Weighs approximately 1lb 10oz with the carrying case.