How can two concentric cylinders create a master-key system in a Yale lock?

In a Yale lock, a master-key system allows a single key to operate multiple locks that each have their own unique individual keys. While there are several methods to achieve this, one approach involves the use of two concentric cylinders within the lock mechanism.12

By utilizing two concentric cylinders, the lock is designed to accommodate two distinct shear lines or operational paths. This configuration enables the mechanism to be actuated by either the specific key assigned to that individual lock or by a master key designed to interface with the shared components of the system. This ensures that while individual users maintain access to their specific areas, authorized personnel, such as a caretaker or manager, can use a single master key to bypass the individual restrictions and open all locks within the coordinated set.12