Air duct bolt. Left.AIR SPRING. Right.AIR SPRING. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Suspension Crossmember Reinforcement to it's mounting point. ABS Wheel Speed Sensor Bolt. Brake Air Duct Bolt. ABS Wheel Speed Sensor. Brake Air Duct. REINFORCED. Support. Suspension Crossmember Reinforcement.