Vixen 3992 is a Mini Porta Alt-Azimuth Mount. The Vixen Mini-Porta come equipped with two fine adjustment handles for whole circle slow motion in both directions, very useful in searching and tracking celestial objects. In addition, these are great mounts for terrestrial viewing.
Gear drives make it a simple matter to precisely track a planet or a ship on the horizon by simply turning the elevation and or azimuth control handles.
The "World-Standard" dovetail attachment system on Porta was developed by Vixen. This allows the Porta to accept various dovetail mounted optical tubes and binoculars.