Built to go everywhere you do, the Field Tube is waterproof with a IPX7 rating and fogproof with nitrogen-filled internal chambers, so you never miss a moment of action. Featuring an oversized focus wheel for easy one-handed focusing and a rugged no-slip grip, you won&&';;t ever want to put it down. Fully multi coated lenses plus a 7 piece (5 group) optical system allows for the best possible viewing experience. Birds, whales, mythical creatures-what will you spot next?