Often called “bacon strips” or “string plugs” due to their appearance, these are the consumable components of the puncture repair kit. They are made of vulcanized rubber soaked in a sticky, self-vulcanizing adhesive. When forced into a puncture hole, the strip compresses and bonds with the tire rubber, creating an airtight seal that prevents air from escaping. They are durable enough to last for the remaining life of the tire, provided the puncture is in the tread area and not the sidewall.