The RAM-B-149Z-GA20U consists of a zinc coated u-bolt base, double socket arm, diamond adapter base and custom high strength composite cradle for the Garmin Rino. Designed into the mount is a 1″ diameter patented rubber ball and socket system with adjustment points at the base and cradle. With a twist of the arm knob, you can move the Garmin Rino motorcycle mount to your optimum viewing position. Included in this package is hardware that will accommodate rails from 0.50″ to 1.25″ in diameter. This mount is designed to hold the following devices: Garmin Rino 520 Garmin Rino 520HCx Garmin Rino 530 Garmin Rino 530HCx Material: High Strength Composite & Powder Coated Marine Grade Aluminum Ball Size: 1″ Rubber Ball „B” Size Note: The „U” in the part number reflects product packaged in poly bag. Related Links:RAM GPS Mounts PageRAM Motorcycle Mounts Page RAM® double socket arms with their distinctive hour-glass shape are designed and recognized to provide the best possible performance for most any application.