SVBONY SV216 3X Barlow Lens offers sharp, bright images with multi-coated elements and edge-blackened lenses to reduce light scatter. It controls aberrations for a flatter view and maintains eye relief, ideal for eyeglass wearers. SV216 3X Barlow Lens transforms your telescope into a high-powered explorer, suitable for planetary observation, reveals intricate cloud bands on Jupiter, rings of Saturn, cratered terrain of the Moon in crisp, turning every stargazing session into a profound celestial encounter. SV135 is stiff enough not to accidentally change focus and smooth enough to rotate without having to hold the telescope lenses base with your other hand. 7-21mm which will give you a wide range of magnification options. This is especially useful in lunar observing where one short barrel twist at a time will bring you closer and closer still to the Moon's craters and mountain ranges to the point where you get the feel of looking down at the lunar surface from an orbiting space station.