I have a kit and haven't used it but here are a couple of thoughts. If there is a raised letter at or very near the tear you will spend a lot of time shaving and/or grinding it flat to make the patch work. If you research the components I believe you will find that it is just rubber reinforced cyanoacrylate adhesive (aka super glue), cyanoacrylate adhesive accelerator, and rubber sheet that matches tire construction. Butyl? I don't recall. At one point I looked it all up and found all the components online for significantly less cost,