What are the two rows of black dots indicating the production date on car glass?

[Tony]

The two rows of black dots indicating the production date on car glass are integrated to show the manufacturing date. Here is an introduction about car glass: 1. Introduction: The production of car glass involves heating the glass to near its softening temperature in a heating furnace, then quickly transferring it into air grids with different cooling intensities for uneven cooling. 2. Function: This process creates different stress levels between the main viewing area and the peripheral areas of the glass. Generally, glass produced this way is zone-tempered glass. 3. Application: The peripheral areas are located in the strong cooling zones of the air grids, requiring full tempering. These areas have better fragmentation and higher tempering strength. The main viewing area is in the weak cooling zone, resulting in larger fragments and lower tempering strength.