The bottom 2/3 of the rear divider and center divider is powder coated steel with a built-in HSEP for added prisoner foot room. We didn't want to give prisoners a birds-eye view of the "good guy" side of the vehicle when you don't have to. The upper 1/3 is polycarbonate and has been designed to allow for prisoner viewing/interaction but not diminish drivers view out the rear view mirror. In fact, the visibility for an officer is nothing short of amazing. The ABS Bio Seat & Floor Pan offer the benefit of biohazard and contraband control with easy clean up when needed. Rather than "force" our customer to take product that they don't need, the Jotto Desk Single Cells comes with Window Armor and an ABS Door Panel for the passenger side only.