Mast rings for attaching wishbones

We want to change the way the wishbones are connected to the masts of our Freedom 35. Currently we use the original wrap around sails. But we want to change these for single sails on a rail. Therefore, we need to change the way our wishbones are fixed tot the masts. Instead of the original mast bands, we want to use metal rings (2 on each mast), as seen in the attached picture.

We have two questions:

  1. What is the exact name of these rings?
  2. Where can we find them?

We hope someone can help us out.

Steven and Frauke from The Netherlands, owners of boat ‘Tumlare’