This heavy-duty car cup holder mounting pedestal features a 25mm (1 inch) ball head and is compatible with ARKON robust series or other third-party 25mm pedestals, including those from RAM mount. It fits easily into car or truck Cup holders and can expand up to 3. 5 inches in diameter. For a complete solution Featuring Akron's Slim-Grip Universal Tablet holder, see model TABRM023.