great in theory [SEP] i love the idea of these in theory you are supposed to wear them on clean skin which makes putting sunscreen on the rest of your face nearly impossible unless you do not mind sunscreen all over the silicone patches there are no instructions on how to clean the patches or why you can use them for only uses is it because it loses it is sunscreen effectiveness or is it because the patch loses its adhesion i found that mine would continue to stick for more than uses however if you sweat a lot they slide all over the place even if brand new which defeats the purpose the also wrinkle over the cheek bones letting sun in which conceivably would diminish the sunblocking i have a small face and found the patches to be smaller than i wanted i think they worked and i did not have any weird tan lines so obviously it wasnt any better or worsw than the sunscreen on the rest of my face overall a great idea that does not quite live up to its promise