Is the SGS testing for mobile phone films reliable? How to read the report?

A: SGS is Societe Generale de Surveillance of Switzerland. It is a globally leading inspection, verification, testing and certification organization, with authority and credibility. SGS test reports are reliable, but there are several key points to understand: ① Report number: Each SGS report has a unique number, which can be verified for authenticity on the SGS official website. ② Testing items: The report is only responsible for the designated items of the submitted samples and does not mean that all items have been tested - for example, testing the light transmittance does not mean that the reflectance has also been tested. ③ Testing conditions: Results may vary under different testing conditions (such as light source, Angle, sample thickness). ④ Sample submission for inspection: SGS tests the samples submitted by the manufacturer, which does not mean that all mass production batches reach the same level (but regular brands will use the SGS results as a reference for mass production standards). SGS report of Woowhead Guanfudun: ①SZIN2606001469PL01_CN: Light transmittance (measured 96.5%) and haze (measured 0.4%); ②SZIN2606001469PL02_CN: Impact-resistant (64g steel ball passes through 1.2m drop ball). Reflectivity ≤0.5%, Mohs 6 hours, wear resistance reciprocating 10,000 times, and water drop Angle 115° are self-test data from the brand laboratory and not SGS test items. The brand clearly distinguishes between SGS testing items and self-testing items in its promotion, which is relatively transparent.