Review on Opticz UV Blacklight Reactive Large Tip Blue Invisible Ink Marker by Barbara Simmons

Latest update: Marker works as advertised. It doesn't seem to help much, if at all, with bird strikes (which is not its intended purpose). Update: I still have bird strike. I think it cut them down but the windows are hard to reach. I will put some light netting on the windows during the autumn and late spring migration season and use it in between as the beating mainly occurs at that time and on certain windows. I use it to avoid bird strikes; I can't see it without a black light, but birds can. Now I finally have the right grid so they can see the window before it's too late with no unsightly things on the window. I suppose I'll have to reapply from time to time, but so far so good. 💕