Benro B2 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 2.5in Maximum Load 44lbs Product or Folded Height 3.9in Leg Size 2 & 3 Head Mount 1/4-20 Quick release Type Arca-Swiss Style (PU60) Weight 1lbs / 0.45kg