The Brunson 802 has a substantial 2" travel for horizontal alignment to known points. Precision roller bearings permit accurate translation of a precision plumbed instrument, minimizing the need for readjustment.
The 802 compound lateral slide, which is constructed using two orthogonally-mounted 802 slides. The 802 therefore has a full 2" of travel in both the X and Y directions. Both slides have a clear vertical aperture designed to allow plummet sightings.
 Standard external 3½"-8 instrument thread mount on top.