The RAM-B-189B-202U consists of double 3.3" twist lock suction cup bases that is connected to a powdercoated metal plate and a B size 1" ball is included The suction cup is designed to have an extra strong hold on any smooth non-porous surface, but for best result, mount the suction cup on a glass or non-porous plastic surface Suction Cup Size: (2) 3.3" Diameter Bases, Total Width 7.95" Assembly hardware included