Purpose-built for the Polarie Star Tracker system, Vixen Optics' Polar Fine Adjustment Unit allows you to precisely align your Polarie for better tracking and sharper imaging. This unit mounts on any 1/4"-20 or 3/8"-16 tripod head, and the Polarie mounts onto the included 1/4"-20 quick release plate on top of it. With the unit in-place, you are able to make minute adjustments to the orientation of the Polarie's polar alignment, with one rotation of the thumb screws moving it 5.7 degrees and a total adjustment range of ±15 degrees. The Polar Fine Adjustment Unit has a payload capacity of 15.4 pounds, so it can easily handle the Polarie plus larger DSLR and lens systems.