This is the telescope that reveals the Sun in all its majesty with the same optical safety and performance demanded by the world’s leading professional research institutions. Its etalon allows hydrogen-alpha wavelength light to pass through safely for viewing the Sun with the naked eye while filtering out otherwise harmful light. As the Sun is an ever-changing star—it is currently approaching Solar Maximum, the end of its 11-year solar cycle—some of its features are moving toward the Earth. This telescope’s patented tuning system captures these Doppler-shifted features with high-contrast views of active regions, flares, and filaments, or it can be easily re-tuned for prominences on the solar rim. Its 90mm aperture, 30mm blocking filter, 800mm focal length, and helical focuser ensure safe, precisely sharp viewing. Clamshell mounting ring is compatible with any 1/4"-20 thread. 40" L x 12" Diam. (34 lbs.)