I'm actually totally skeptical about such a 'magic bullet' concerns. But at the price I thought, try it a try! With rockfall in my field of vision abgemeldetes car gets no MOT! And without Tüv no admission! So a real quandary. The manual is okay. Aaaber: Only is there, Do not use in direct sunlight, then you see that the repaired area is in the sun. Yes, watt because nu? Without UV light, the finished product remains liquid long. Later, a second attempt followed by sunlight went super! Something bad quickly, but it was noted in the instructions. Only, the excess adhesive was worried; I meant it to be good. I just nachh three days taken once the time and with a Ceranfeldschaber obtuse angle as possible (even so in the manual recommended!) Scraped the excess stuff. The old stones, a point with about lens size inside, you can at most guess even if you have himself treated the place! :-) For the money always recommended!