The Monoball Z1g+ Ball Head from Arca-Swiss has a heavy-duty load capacity of 132 lb, and employs a Motion Related Gravity Control system for variable and bi-directional friction control that is independently operative on both axes. The head is smaller and lighter than its predecessor, the Z1.
The Z1g+ can perform 360° pans on both the base of the head as well as the top mounting plate. There are separate locks for both panning axes as well as one to control the movement of the ball. A bubble level helps you align your camera to the horizon.