When the telescope is pointed at or near the zenith (directly overhead), mirror diagonal telescope allows for more convenient and comfortable observation. SV188P uses a high-reflective dielectric coating that can achieve a reflectivity of 99%; more light means you will get brighter pictures. SV188P is a 2-inch diagonal telescope; suitable for 2-inch telescopes and eyepieces; includes a 2-inch to 1.25-inch converter; can connect to 1.25-inch eyepieces. Allows for astronomical observations in a comfortable position. Just like looking in a mirror, the image is correct up and down; left and right are flipped. The brass pressure ring effectively protects the eyepiece from damage during use The SVBONY SV154 26mm super-wide angle 2" telescope eyepiece uses premium optics that are fully multi-coated for crisp; clear images; Have a super wide-angle observation experience works well for terrestrial observations as well as for views of the Moon; planets; and deep-sky objects. Large Field of View The eyepiece has a large field of view and the field of view is as high as 72 degrees. Excellent Optical Performance with high contrast, high resolution and excellent flat field characteristics. Durable Comfortable The eyepiece is equipped with a detachable and collapsible soft silicone eye mask for long-term observation. Waterproof 5-piece 3 group eyepiece structure, make it moisture proof and waterproof Use for viewing,especially for large-area deep-sky objects, will provide high light transmission image quality. In the long-term use, both in the planetary and deep space, there are good performances. No additional chromatic aberration introduced, making it easier to make long-term observations