The difference between the Ultimate Ball-Head and other Ball=Heads is the angle of the clamps that hold the ball. The Ultimate Ball Head clamps are at a 45-degree angle and other Ball Heads they are horizontal. The angle of the ball clamps affects the range of motion.
You can also rotate the Ultimate Ball-Head 180 degrees and then the range of motion is from forwards to straight up which is excellent for night sky photography. All Acratech Ball-Heads are designed to be lightweight and rugged for the active outdoor photographer. The open structure lets moisture, dirt and debris fall through instead of being trapped inside a socket. The item "Acratech Ultimate Ball-Head with Arca Swiss Quick Release Plate" is in sale since Tuesday, November 20, 2018. This item is in the category "Cameras & Photo\Tripods & Supports\Tripod Heads". The seller is "fmkjr" and is located in Beaver Falls, Pennsylvania.This item can be shipped to United States.