Abstract: A cylindrical locking core suitable for retrofit and new installations has a coupling to releasably engage a driver in a locking system. The coupling, for example, a clip, has a base which fits into a channel in the core, to grasp the core. The clip also includes two opposing flexible, resilient arms to releasably grasp the driver. The arms have rigid flanges which engage recesses in the driver. The core may be disengaged from the driver by rotating the core relative to the driver, using a change key. When the core is in use, an operating key extends through the core and an opening in the coupling, to engage the driver, to open and close the lock system.

Abstract: A cylindrical locking core suitable for retrofit and new installations has a coupling to releasably engage a driver in a locking system. The coupling, for example, a clip, has a base which fits into a channel in the core, to grasp the core. The clip also includes two opposing flexible, resilient arms to releasably grasp the driver. The arms have rigid flanges which engage recesses in the driver. The core may be disengaged from the driver by rotating the core relative to the driver, using a change key. When the core is in use, an operating key extends through the core and an opening in the coupling, to engage the driver, to open and close the lock system.

Abstract: A bitted substantially rigid extension adapter is provided which may be applied to an existing operating key thereby forming a control key assembly. The extension adapter is provided with fasteners for secure attachment to an operating key. The extension adapter may be made of metal. The bitted portion of the adapter may activate one or more control tumblers in a removable locking core housed within a locking mechanism. The adapter and key, when combined, may be used to remove the locking core from the mechanism.