RAM Twist-Lock Suction Cup Double Ball Mount RAM-B-166U 7934423901041, is ideal for vehicle windshields and other nonporous surfaces. The base is compatible with RAM Mounts diamond ball bases, ball and socket technology allows for adjustability that is near-infinite. Made of high strength composites for durability and reliability. This entire setup is compatible with the SlipGrip RAM-HOL and SlipGrip Pro Mounts Brackets, Brackets are sold separately according to the phone and case requested for.