Benro B3 professional ball head offers separate drag adjustment and lock knobs, for a dual action design. Magnesium alloy components insure even greater performance and lighter weight. Specifications Top Plate or Base Plate Diameter 2.9in Maximum Load 66lbs Product or Folded Height 4.3in Leg Size 3 & 4 Head Mount 1/4-20 Quick release Type Arca-Swiss Style (PU70) Weight 1.5lbs / 0.68kg