SPRMCLAMPL29 features a clamp with a pole that extends upward from 17 inches to 29 inches high. The tough plastic clamp secures to tables, desks, counters, and other clampable surfaces from approximately .4 inches up to 3.1 inches thick. The metal pole's 25mm (1 inch) ball is compatible with selected Arkon Robust Series and Ram Mounts adapters and holders (not included). This clamp and extendable pole are perfect for areas where space is at a premium and flexibility vertically is needed.