Goniometers allow for precise angular adjustment of an object about a fixed point located above the center of the mounting surface. Stages with smaller radii can be mounted on top of same size stages with longer radii to provide motion about a common point in two different axes. Each stage features precision movement along a dovetail design with a vernier scale for high-resolution measurements and movement repeatability. A locking thumbscrew allows each stage to be held securely in place. Stage material is a durable black painted brass. 40mm square, 8mm thick top mounting adapter plate #58-290 mounts to M3 holes and provides a counterbore for ¼-20 or M6 socket head cap screw. Compatible with the following stages: #55-029, #55-030, #55-031, #55-838, and #55-839.