The RAM-B-166-AP18U consists of a 3.3" diameter suction cup twist lock base, double socket arm and high strength composite cradle. The suction cup, twist lock base is designed to have a strong hold on glass and non-porous plastic surfaces. Designed into the mount is a 1" diameter patented rubber ball and socket system with adjustment points at both ends of the socket arm; this with a twist of the arm knob, allows you to move the mount to your optimum viewing position.