First I'd like to say that the idea is a very good one and the stickers are made basically perfectly. You can't tell you are wearing them on your nails, they just look like a very, very light nude nail polish. If you apply a sticker, that is a bit too narrow for your nail, you will see the edge but only from the side.
They are easy to apply, which is also a very positive thing in my opinion.
To take them off you can either pull them off your nails, scratch them off or remove them with a nail polish remover, also quite easily.
Now, I had the shields on my nails for five and a half days before I decided to take them off.
The pack says that they last up to 14 days and I think that this is maybe even possible, provided that you don't play with your nails, don't get anything stuck between your nail and the shield ( like paper or so), don't get in touch with water too much etc.
As I already mentioned, I took them off, after two of them ripped off a bit at work and you could tell that I had a layer of something on my nails. I took off the two shields and decided to stick on two other ones which were left over in the pack. However, they were not sticky at all any more at this time and I didn't know why, because they were all stuck to some foil and covered with another one. But, they came in a sealed foil "envelope" and once you open it, air gets inside and also in touch with the shields that are left in there. So, in my opinion the shields reacted with the air and were not sticky any more. ( for some reason they were sealed airtight, right?)
As a result I decided to take off all the other shields too and to use my nail treatment for the next days again until I get more of the shields.
But I have to say that my nails managed to grow about 1 or 2 mm and they didn't break yet, which is a nice outcome I think.