Although designed to be mounted on a windshield, this 4 1/2" aluminum arm attaches to other smooth, non-porous surfaces, such as a desk or countertop. The large cam-operated suction cup at the base of the arm applies a firm, lasting hold until you release it with the flip of a lever. The arm has a locking hinge that adjusts its projection above the mounting surface, while a steel ball at the tip of the arm clings to a magnetic disc (not included) that attaches to your phone; it holds securely but lets you adjust the viewing angle as well as rotate the screen to a portrait or a landscape orientation.
This arm comes with Steelie FreeMount and magnetic-mount kits; when purchased on its own, it can be used with a 3/4" magnetic disc you buy separately or already own as part of another Steelie mount system.
Please note that using items mounted to a windshield while operating a vehicle may be prohibited in some jurisdictions.