Battery tray nut. A Nut used to retain the Fender Apron to it's mounting point. A solid metal or plastic block with a threaded hole in the center which is used to tighten or adjust the Cowl Panel Reinforcement. Battery Tray Nut. Horn Nut. Nut to secure Bumper cover. Radio Bezel Nut. Included with: Apron/rail assembly, Front Reinforcement.