We have a similar system, with a ring each side of the sail, held by webbing through the grommet.

Conventionally, you hook the ring over a horn.

Instead, I have a Wichard snap hook (you can use a snap shackle) on a rope attached to the mast at the right length.

The advantage is that once you hook on to the ring, it will not come adrift if the sail is flapping.

Our 2nd and 3rd reefs are with a hook that I put on the ring, then pull down and make off to a cleat, before hauling the main halyard back up. This is handy if the rings are a long way up.

I like it MUCH better than the traditional horns.

We just took the mast out today, so I cannot take a good photo for you til Spring. If you want one with the mast and no sail, Email me