Opto Sigma's GOHB-A Goniometers are all-brass stages having standard 40- and 60-mm platforms with higher than average rotation-axis heights. They are driven by a high-tolerance worm-gear mechanism which, along with its high precision v-groove guides, yields rotation-axis accuracy less than 50um. As with all goniometers, the axis of rotation is situated parallel to and above the mounting platform but they are also designed to be stacked so that they have intersecting orthogonal axes of rotation. In this configuration, they have capability for orbit-like positioning about a single point. The GOTB series of goniometers are lockable and finished in a RoHS-compliant black chrome.