Antlia 3nm H-Alpha Pro Series Filter - 31 mm - HA-PRO-3NM-31 iOptron iAFS Electronic Focuser The bundle includes a 4

The bundle includes a 4 lb counterweight and counterweight shaft

a focal ratio of f/7

The ZWO IR-Cut Filter blocks infrared light from reaching the sensor of your CCD or CMOS camera or your expensive H-alpha filter

Includes a counterweight to counter-balance the telescope on this mount

They can be attached to either side of each axis to accommodate right or left-handed users

Antlia 3nm H-Alpha Pro Series Filter - 31 mm - HA-PRO-3NM-31 iOptron iAFS Electronic Focuser The bundle includes a 4This very narrowband 3 nm H alpha 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. Important! Not for use when viewing or imaging the Sun! Antlia 3nm Pro Series H Alpha Filter 31 mm Unmounted This Antlia H alpha Pro narrowband filter optimizes the FWHM (full width half maximum) to a 3nm bandpass. As the bandwidth becomes narrower, the 3nm