The RAM-B-166-202U, twist lock suction cup mount consists of a 3.25″ suction cup locking base and round base end. 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. The round base is a flat 2.5″ diameter base; this mount has pre-drilled holes, including the universal AMPS hole pattern. Material:Powder Coated Marine Grade AluminumBall Size: 1″ Rubber Ball “B” Size Note:The “U” in the part number reflects product packaged in poly bag.