Giottos MH3300-658 Ball Head (Black) Arca-comaptable Load capacity: 28 lbs. Calibrated tension control knob QR plate with 1/4-Inch threads Base with 3/8-Inch socket Weight: 2.12 lbs Load capacity: 28 lbs Base with 3/8-Inch socket QR plate with 1/4-Inch threads Height: 5-Inch