Collar Screw. Steering Idler Arm Bolt.
540I. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Steering Idler Arm to it's mounting point. M5.
Steering Idler Arm Bolt
Fits 540i, 740i, 740iL, 750iL, M5
540I. M5.