We build optics with foresight. Thoughts such as, spend enough time on the water, and your equipment will spend some time in it. The H2O TM series binoculars are O ring sealed and nitrogen purged to completely lock out moisture should you spill, take one overboard, or simply run into foul weather along the way. Rubber armoring with textured pads gives you a grip in slippery situations. Multicoated optics and premium quality BaK 4 prism glass maximize light transmission and image clarity. You'll quickly see how a little planning on our part goes a long way to magnify your adventures on and around the water. BaK 4 prisms for bright, clear, crisp viewing Multicoated optics for superior light transmission 100% waterproof O ring sealed and nitrogen purged for reliable, fog free performance Non slip rubber armor absorbs shock while providing a firm grip Fold down or twist up eyecups Large center focus knob for easy, precise adjustments Longer eye relief