Hold down screw. W/O DUAL BATTERY. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Backup Sensing System Module to it's mounting point. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Brake Vacuum Pump to it's mounting point. Battery Hold Down Bolt. Air Pump. Battery Hold Down. HEX Flange HEAD. Parking Aid Control Module. Power Brake Booster Vacuum Pump. Processor screw.