The RAM-B-166-GA21U, twist lock suction cup mount consists of a 3.25″ suction cup locking base, socket system and custom high strength composite cradle for the Garmin nuvi. The mount is designed with a RAM 1″ diameter patented rubber ball and socket system that has adjustment points at both ends of the double socket arm; this allowing for almost infinite adjustment and perfect viewing angles. Simply attach the suction cup base to the windshield of your vehicle for an easy and safe way to view your handheld device in your vehicle. High quality materials ensure your electronic device is safe, secure, and within easy reach. RAM’s patented design also dampens shock and vibration helping to extend the life of your mobile device. This mount is designed to hold the following devices: Garmin nuvi 300 Garmin nuvi 310 Garmin nuvi 350 Garmin nuvi 360 Garmin nuvi 370 Material: High Strength Composite and 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 Suction Cup 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.