Vixen Optics redesigned their tripod for this version of the Porta II Tall Alt-Azimuth Mount to give it a higher maximum height for use with refractor-style OTAs or for taller people who don't want to hunch, while maintaining the sturdy and stable Alt-Azimuth head that is easy to set-up, use and transport. With its standard Vixen dovetail plate and 20 lb payload capacity, you can attach Vixen and many non-Vixen optical tube assemblies, or bring multiple OTAs for a viewing session, and simply and quickly swap them to suit the subject. This most basic of mounts is ideally suited for quick astronomical or terrestrial viewing. Two control knobs, one for each axis, allows users to make small and precise adjustments for tracking subjects. Its two 120-tooth worm gears let the altitude and azimuth travel a full 360° circle.
The Porta II operates without locks and clutches, but rather with a friction system. This means you can simply move the mount by hand to quickly find your subject, then use the slow-motion knobs to track. Since many different OTAs can be mounted, there are adjustment screws on each axis to add more or less tension, based on the weight of the OTA. Also, depending on the design of the OTA, you can change the orientation of the flexible handle position to be correctly orientated for comfortable use.
An aluminum 2-section tripod comes with the mount. It has a height adjustment range from 40 to 51 inches. A solid center bolt lets the mount also turn a full circle and makes the mount easily detachable from the tripod to mount on heavier tripods. A nylon carry-bag, specifically designed to fit the mount and tripod, is included to make getting to your viewing spot easier.