Unlike others here, I'm real happy using the Park glueless patches (I currently have one on each front and rear) and after 4 months neither has given out. Since I always carry a spare tube, regular patch kit, and a pump, I figure I'll keep riding them until I have a problem and see how long they last. My kit did come with a small piece of sandpaper and I used it to make sure that I roughed the area up very well (one of the patches was even on a seam). I'm sure the vulcanizing patches are better, but I can't complain about what my $2 trial with the Park glueless patches have given me.