Universal tablet holder, top. 1/4'-20 x 1' thread. Ball joint: 1' rubber ball, size B. Made from high-strength composite materials and steel. Weighs 41 g. Features: Modular expandable. The RAM Mount holder system is modular in design. Each holder consists of a base, an arm, and a headpiece. Depending on the holder, these are either screwed together or usually connected via a ball joint. This provides flexibility in orientation and, combined with the material, ensures a shock and vibration-damping effect.