The 4.5" Center Grip Head consists of a pair of rotating aluminum discs attached to a junior 28mm (1-1/8") stud. The discs have two different sized "V" jaws to accept any accessory with a 5/8" or 3/8" mounting stud or tubing. They are often used for clamping ears from an overhead or butterfly system. Features U-shape rotating disc holder welded with junior 28mm (1-1/8") stud which is specially designed for centering the weight over the stand..