they are best set aside for true road emergencies
These are really designed for thin tire casings as found on bikes, motorcycles and utility trailers.  They will work on car tires but it takes practice to avoid damaging the plug (rendering it useless).  Given the cost, they are best set aside for true road emergencies.  Besides, the brass point is not really crimped to the plug so they are not what I would consider safe as a repair for longer term on road use.  The big downside is the need to clean the tool with solvent after each use.  The gum from the plugs gets all over it and will make the next use difficult.  Neat idea and seem to be a hit with the motorcycle crowd.  Cost point is just wrong for anything other than an emergency back up.  Buy true patch plug combo's if you want to repair a tire.  Yup, you need to at least partially dismount the tire, but its permanent and safe if done right.
Rating: 3 stars