I remember seeing the "Speedy Plug" brand of those at the Dot shops. They used them on our tires if it was just a nail hole.Google Plug Patch. This is what we use, recommend by tire mfgs. It's a patch with a plug in the center, must be installed from the inside, plug pulled through to the outside. The plug fills the hole and helps keep rocks and water out, the patch seals the hole, keeps air in. The first thing that should be done when patching is to use a liquid buffer-cleaning fluid and a scraper to clean the silicone release agent from the inside. If the tire is buffed before this is done the silicone will be buffed into the rubber and the patch won't stick.