Usage: With its four-element optical set and high-transmission coating, this eyepiece delivers clear, with increased contrast Essential: It is essential for friend Usage: Whether you ' re gazing at the, planet, or objects, the 43º apparent field of view will give you an immersive viewing Suitable for: Perfect for astronomers and professionals alike, it is designed to your observing Usgae: Your with the 40mm Eyepiece and explore universe like never before