I work on sites and i always drop my phone, so it it always in a case and always has these protectors on it. I have used lots in the past and some are totally s---t but these are abosolutly perfect. They are sticky enough theat they stay in place and if you never got it straight first time you can lift it gently and place it back down and just push bubble out to the side.
If you want to see full review on how to apply one of these and get it right first time evry time then go to my YouTube channel at GadgetKingreviews and you will see how it it done, without getting dust behind them or any other contaminents and you should be fine.
I wll leave a li k below and my phones are alway in mint condition aftyer the 2 hears contract are up. The video is below go watch and suvbscribe to my channel lots of give aways and free tech and gadgets, pres bell button top be notified of new reviews and you will be watching unbiasd reviews, because I puirchase all my products to review so I can say what I want about them if they are S--t then I will say they are. Thanks..!