Adapter Doublestack 40mm

This adapter allows you to attach a second Coronado H-alpha (Etalon) filter to a SolarMax II telescope. Just make sure that the filter diameter matches the telescope's aperture. Using this method, called doublestacking, means the bandwidth of the filter decreases from below 0.7 Å to below 0.5 Å.

SolarMax III telescopes already have a suitable thread at the front of the OTA, so an adapter is not required.