Produced from PolyCarbonate (PC) a material that can withstands extreme loads in that point.
The gooseneck is shaped so if you are using the cuningham going inside the boom, the edges are smooth so it will work easily.
Simply stick it to your mast with a methacrylate glue (plexus). Remember about sanding the part before applying glue.
Designed and produced for the 43mm mast diameter and 40 mm boom width, with 8 mm hole for a pin/screw.