What is a bottom air diffuser? The glass on my shelf above the two crispers broke and I don't know what the difference in an air diffuser and the glass. Also, do these drawers come with grid lines because I don't remember the previous ones having them.
The bottom air diffuser is the air return from the fresh food compartment to the freezer compartment. The shelf has nothing to do with the diffuser and the glass has not got the grid lines. The photographer placed the glass on the grid to take the photo. The grid is so the size can be determined since each square is one inch.