Amzer - Boat Helm Tablet Mount Description Amzer's Universal Boat Helm Mount for Tablets features an innovative holder that adjusts to fit any 7 - 12-Inch tablet and a 4-Inch arm. The mount base fits rails and posts up to 33mm diameter. It’s as simple as that…..Perfect for your next road trip or your drive around town. Safety first……With Amzer’s Boat Helm Tablet Mount for your device!