Manfrotto 124 Clamp Pivot for Boom Shafts For 19, 20, 25 & 28mm diameter

Ultralight AC-CSB-UB coarse thread ball clamp with blue knob for large buoyancy arms

Ultralight AC-CSF coarse thread ball clamp with black knob

Ultralight AC-CSB ball clamp with black knob for large buoyancy arms