The RAM-B-224-1U suction cup base consists of a 3.3" / 8.38cm diameter RAM® Twist-Lock™ suction cup connected to a RAM-B-238U diamond base with a 1" / 2.54cm B size rubber ball. The RAM® Twist-Lock™ suction cup base is a fan favorite for use on vehicle windshields, and provides an extra strong hold on any smooth, nonporous surface. Complete your mount by attaching a B size RAM® double socket arm and device holder.