Waterproof (up to 1 meter for 5 minutes) and fog-free with nitrogen gas filling High-eyepoint design provides a clear field of view even for eyeglass wearers Turn-and-slide rubber eyecups with multi-click facilitate easy positioning of eyes at the correct eyepoint Wide field of view Multilayer-coated lenses and large objective diameter for optimal image clarity Rubber armouring for shock resistance and a firm, comfortable grip Eco-glass optics are free of lead and arsenic Aspherical eyepiece lens eliminates image distortion.