The rubber ring is called a grommet and it lines the edge of holes to help protect the cord.
When I started drilling glass bottles to make bottle lamps, I would use a hot glue gun to help hold the cord in place. It was messy and eventually it would come out anyway. This wasn’t what I really wanted my end product to look like and there had to be a better way. If I would have taken a moment to actually look at other glass lamps, these little rubber devices would have saved me a lot of hassle.
What size grommet or rubber ring do I need? – A frequently asked question that is really hard to answer because of the many variables. You have the thickness of the electrical cord plus the size of the hole that you drilled that come into play.
If you are looking for a specific size to get then it would probably be your best bet to purchase a rubber grommet pack that comes with multiple sized grommets. Having a nice snug fit will ensure that your cord is both protected and secured.
We would like to thank Amy for sending us this question about Rubber Rings.
Remember, if you have a question you can leave us a comment on the post or shoot us an e-mail.