This product is kind of special screen protective glass which is designed for solving the screen abrasion caused by frequent writing and touching in daily life; It is kind of update technology based on the third generation electrostatic crystal scratch resistant(3 layer glass with filling), named carbon scratch resistant: it has been tested by 10000 times repeated scratch resistant test, and the intensity of it reached 5H(similar to the strength of rigid metal surface). Meanwhile, it can also ensure normal screen sensitivity.