Pentax 70940 PF-100ED Spotting Scope with Field Case Large 100mm objective lens for bright viewing in all lighting conditions Utilizes the XL telescope eyepieces renowned for their sharpness, field of view, contrast, and freedom from aberration Extra Low Dispersion (ED) optics incorporate Lanthanum Crown (rare earth) glass elements for optimum resolution Accepts all standard 1 1/4-inch interchangeable telescope eyepieces Waterproof, fogproof, and nitrogen filled