This is item #14 as shown on the diagram, a reliable ring retaining product.

To use this ring retaining device, simply place it in the designated position as indicated on the diagram. Make sure it fits snugly to ensure proper function. When handling, be careful not to drop or damage it. For maintenance, keep it clean and dry. If it gets dirty, you can gently wipe it with a clean cloth. Check regularly for any signs of wear or damage, and replace it if necessary.