Product review (5 stars): Effective, easy to apply.
This stuff works very well.  It is easy to apply and I expect it to last many years.  I used it or, perhaps a very similar item many years ago to cover some small pinholes on an old sheet-metal roof and along the edge.  The old job is still good after at least 15 years, probably more like 20.  It is not cheap, but it is top-quality.