Antlia 3nm SII Pro Series Filter - 31 mm - SII-PRO-3NM-31 finderscope except NOTE: The black plate

except NOTE: The black plate is shown in a photo to illustrate the attachment and result

The optics

or want to mount an Explore finder on another telescope brand

preserving clarity and true color

Antlia 3nm SII Pro Series Filter - 31 mm - SII-PRO-3NM-31 finderscope except NOTE: The black plateThis very narrowband 3 nm SII filter from Antlia is part of their Pro series and is of the 31 mm unmounted variety. It is normally used in a 1. 25" 31mm filter wheel, where it drops into place. Antlia 3nm Pro Series Sulfur II Filter 31 mm Unmounted This Antlia SII Pro narrowband filter optimizes the FWHM (full width half maximum) to a 3nm bandpass. As the bandwidth becomes narrower, the 3nm Pro narrowband filters enhance contrast of emission targets