The RAM-B-166-GA39U consists of a 3.25" suction cup locking base, socket system and custom high strength composite cradle for Garmin nuvi 3000 series GPS devices. 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 device. RAM’s patented design also dampens shock and vibration helping to extend the life of your device. This mount is designed to hold the following devices: Garmin nuvi 3450, Garmin nuvi 3450LM, Garmin nuvi 3490LMT, Garmin nuvi 3750, Garmin nuvi 3760LMT, Garmin nuvi 3760T, Garmin nuvi 3790LMT, Garmin nuvi 3790T.