A dual arm machine can have both arms measure certain features. This region where both arms can measure features is called the overlap. This property value defines the percentage of overlap to consider. For example, if you have 100 mm of overlap, and you enter 50% for this property then the software only considers 50mm as overlap. If a feature falls within this range and AssignArms is set to True, it becomes a candidate for the software to choose the best arm to measure.