Zeiss Astroadapter for Conquest Gavia 85The Zeiss Astroadapter for Conquest Gavia makes the Zeiss Conquest Gavia 85 Spotting Scope compatible with standard 1. 25" 1 OE" Barrel Astronomical Eyepieces, transforming your traditional spotting scope into an exceptional astronomy observation tool! The focal length of the eyepiece should not fall below 8 mm, as this could cause the exit pupil to be significantly smaller than your pupils which are fully dilated at night when you're stargazing.