Why should mobile phones be coated? To prevent the screen from breaking, scratching is the two main reasons, a good-tempered film can save thousands of dollars in maintenance costs, but also to avoid screen scratching caused by light transmittance decline, affect the display effect, then how to choose a high-quality mobile phone film?
Mobile phone film is generally divided into 
glass screen protectors and plastic two major materials:
1, tempered glass has HD < Half pack, Full pack (cup size) >, anti-blue, green light, anti-peeping film,
2, plastic including hydrocoagulation film, frosted film, HD soft film (hard)
The most important function of the mobile phone film is, of course, to prevent the screen from falling, one thing for sure is that the plastic is definitely better than the tempered film, the tempered film will absorb a lot of impact when broken, and the ab glue in the middle can also disperse it, which is equivalent to two layers of soft and hard protection! Plastic film is for those who do not often "hand slip", but do not want the phone to scratch or have higher requirements for the appearance of the phone (can be perfectly fitted), the fall resistance is worse than the tempered film, after all, the plastic film will not be broken, only a little starting buffer effect, most of its impact is still on the screen. Divided into half package and full package, in the Apple 5s (SE1 generation) and above, the former is a flat screen (2D), toughened film can be perfectly fitted, more than 99% of these models are fully coated. There will be no white edges! And Apple 6 to 11pRomax (se2 generation) are using the edge screen, the tempered film cannot all fit, there will be a white edge around the screen (Apple x to 11 arc is small, the white edge can be ignored), so there are four solutions on the market:
1, with white edge filling liquid to make up, as long as you buy the full envelope will come with a bottle, is a transparent oil, but after a long time will absorb dust
2, half envelope: only fit the screen display area, because the surrounding coverage is less than, so can only protect the screen is not scratched and positive landing, the protection ability is weak
3, air bag film: the middle is tempered glass, surrounded by resin (PC) outside, the best fitting effect, neither fall resistance nor white edge!
4, with the frame film: tempered film sprays a circle of black or white paint to make up for the visual deficiency, but after pasting the arc edge will "disappear", more painful, but the protection effect is very good!
Anti-peeping film: suitable for work with high confidentiality, it can also avoid others from peeking passwords or chatting next to it, as long as the Angle of view is slightly tilted, you can't see the screen content at all, protecting secrets from being leaked!
Green light, blue light film: pure business exaggeration, cannot prevent blue light injection, but also cause the display of color difference, and the night view mode of Apple mobile phone can reduce blue light, the real anti-blue light film to more than 300 yuan! Highly recommended to buy!
Hydro coagulable film: it can fit the screen better, the price is also low, it is not easy to scratch, but there will be wrinkles or collapse when encountering hard objects, it is one of the solutions for curved screen, suitable for people who do not have high requirements for the ability to fight against falling or do not want to change the film often.
Frosted film, e-sports special film: not easy to stick fingerprints, smooth and sensitive operation, of course, bear's paw and fish cannot concurrently, the picture looks like separated by a layer of fog, currently based on glass.
Hd soft film: like the film that comes with the factory before, it cannot fit the screen well, the wear resistance is poor, and now it is almost eliminated, not recommended to buy!
Three important parameters of the lower tempered film are briefly introduced.
Transmittance: This is the direct factor that shows the effect is good or bad, the higher the higher the proof that the lighter through the film, the better the effect, the greater the brightness! (HD {half, all-inclusive} > Hydro coagulable film = HD soft film > Frosted film > Blue, green light film > Anti-peeping film)
Oil repellent layer: divided into manual spraying, plasma spraying, vacuum plating, artificial in about two weeks of use will fall off, can no longer prevent fingerprints and feel very astringent, the roadside stall 10 yuan a piece, and Taobao 9 9 pieces of three are this; Plasma is used for about 3 months, the cost is very high, generally can adhere to the membrane scrap, recommended to buy.