**Referred to as a tension strut, per BMW it is mandatory to replace in matched pairs** Your BMW's tension strut is designed to locate the entire front strut assembly. It is under constant tension from suspension movements as well as road forces. Over time the inner bushing is known to fail allowing for this assembly to move freely resulting in poor handling, vibration, and noises. FCP Euro recommends replacing this control arm in matched pairs per BMW TIS recommendations.