Zoom from low power to high power instantly with SVBONY SV135 1.25 inch zoom eyepiece. SV135 fully multi-coated zoom plossl eyepiece zooms to any focal length between 7 mm and 21 mm. Pick the best magnification for your object and enhance your view! SV135 zoom eyepiece has M28.5*0.6 threads on the bottom very convenient for connecting filter; compatible with 1.25-inch telescopes and accessories; works great for photography. 15mm long eye relief distance ensure relaxing observation and keep your eyes comfortable, especially for users who wear glasses; the rubber eye guard provides comfort and blocks unwanted stray light. Suitable for observing a variety of celestial targets. SV135 zoom eyepiece could bring you a better observation experience in a comfortable situation with high-contrast imaging; designed primarily for viewing lunar surfaces; jupiter and saturn; nebulae; clusters; and diffuse nebulae. SV165 Mini Guide Scope Support sensitive auto guiding cameras for easy guide star acquisition. 45mm Tube Travel. Improved image adjustment accuracy. For clearer images when used with astronomy cameras and telescope eyepieces. Sturdy metal base. Fits most telescope finder-shoe bases. Does not take up weight, easily fixed. Brass pressure ring. Effectively protect the eyepiece from scratches.. Adjust the set screw to firmly fix the eyepiece, and will not easily slip out of the interface. 30mm object lens, and back focus distance can stretch up to 45mm. Please pay attention to stretch to the end.