Those are great. Just bought some. Will keep a few in each car if only to get to a safer place to deal with a puncture. I keep 12v compressors in the cars.
My tire shop won't fix tires over 5 years old. I had to do one of those push in things Porsche Tech was talking about. Yeah, barely got it in and there was that potential to slip and get hurt.
(edit) These came today. Seems like a gimmick, they are hard steel with a coating of sealant. They might get you a few miles but my thoughts are they will work their way back out or just crack under the pressure of a rotating tire. I would not trust these for any length of travel or highway speeds. I found some reviews on other listings and there are plenty of comments on how iffy these things are. Sometimes they work for awhile and sometimes they either break during installation or don't seal well. Several reviews suggested using silicone or other type of sealer to help with threading in and a better overall seal.
Anyone that said these can be used near the edge of the tire are living dangerously.
What I bought.