This review needs to be prefaced with an important fact: I have no spare tire and don't have run flat tyres.I decided that I was sick of worrying about what I'd do if I got a puncture in a part of the country were 265/40R18's weren't common (these are for a Porsche, they're an extremely uncommon size).  I went on a bit of a tyre repair buying spree, buying this in addition to a giant bottle of slime goo and a more generic set of plugs.  My car did come with it's own tire goo, but I didn't want to rely on OEM tire goo as my only option.Well, I got a puncture last night that left my tire completely flat when I got back to my car this morning.  All of my previous punctures kept air just fine so I could get to the tire shop for a proper repair, but this one wouldn't hold air even with the screw still in the tire.I figured this would be just as good a time as any to try out this product, since the tire just didn't hold air at all.  Really easy to use, the instructions were simple and clear.  I highly recommend their suggestion of using water on the plugs, otherwise it catches on the tool.  I put the first plug in, and it was leaking air just as much as with the screw.  I put in a second plug and it let out just a little bit of air, but much less.  I thought I'd just leave it at that, but in the end I put a third plug in.  It was completely sealed up, and water doesn't bubble up on it.  That was about 6 hours ago, and I just checked and it's held the same pressure as when I filled it up at the gas station.  I took the wheel off the car because I was safely in a garage, but I could see doing this on the side of the road with the Porsche air compressor.This isn't an expensive or interesting product, but what I love about is that it gives me more confidence when driving my completely impractical car on road trips!  I'm buying a new set of tires (the puncture was on a nearly worn out set of tires), so I can't attest to long term reliability, but I can say that for punctures which leave the tire intact, this product can help you get to a place to fix your tires for real!  I don't know whether this is considered a long term fix or not, but I won't be using it for tires I plan on using on the freeway.