Baader SunDancer II H-alpha filter

SunDancer II H-alpha filter, 0.60 ±0.1 Angstroms
The Baader SunDancer II (with heated H-alpha Etalon from
SolarSpectrum) transforms an existing telescope quickly and easily
into a professional H-alpha telescope! For telescopes up to 80mm
opening, you do not need any additional accessories: The SunDancer II
already includes an achromatic (!) 3x telecentric with T-2
Connection; the entire SunDancer is simply placed between star diagonals
and eyepiece and connected to a power source. Then it heats up
automatically to the optimum operating temperature. Even with long ones
observations, no readjustment is necessary. A fine tune of the
Pass line for adapting to different telescope systems is above
the checkbox possible; via the micrometer screw it can be quickly in
the blue wing of the H-alpha line to be shifted
Doppler effect of fast H-alpha events on the Sun
to balance.