Featuring time-proven porro-prism optics and extra large objective lenses, the PF-Series of Spotters produce sharp, clear images with minimal chromatic aberration. All models feature lightweight magnesium-alloy bodies with waterproof/fogproof construction with a JIS Class 6 rating. High-refraction, low-dispersion, Lanthanum Crown (rare earth) glass elements are used for exceptional viewing and image quality. The 31.7mm American-standard eyepiece receptacle on each model accepts six different types of optional eyepieces. These versatile, heavy-duty Spotters are perfect for demanding use out in the field wheater you are out looking for wildlife, birdwatching or stargazing.