Coronado 40mm Double Stack Adapter Ring (AP185)

Coronado 40mm Double Stack Adapter Ring

The Coronado 40mm Double Stack Adapter Ring is required to double stack an SME-40 external primary Etalon, double stacking an original 40mm Coronado or Coronado II telescope such as an SMT40 or PST. Telescope and double stacking filter sold separately.
Reduces original .7 angstrom bandpass of the Hydrogen-Alpha telescope to .5 angstrom, dramatically increasing visibility of surface detail such as granularity and active regions on the surface of the Sun.