SUNWAYFOTO FB-36III 40lb Max load Tripod Ball Head Arca Compatible Sunway FB36III Features DDC-42i 42mm Screw Knob Clamp. Accepts QR's from RRS Wimberley, Arca Swiss, Kirk, Markins, etc. 40lb Max load Elliptical Ball for progressive resistance Weighs: 310g (10.8 oz)