This product is a kind of special screen protective glass whick designed for solving the screen abrasion caused by frequent writing and touching in daily life. it is a 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 10.000 times repeated scratch resistant test, and the intensity of it reaches 5H ( similar to the strength of rigid metal surface), meanwhile, it can also ensures normal screen sensitivity.