Abstract: The invention is in respect of a lock having a body and an actuator arrangement which is displaceable relative to the body between an inoperative condition and an operative condition. The actuator arrangement is capable of operating a device such as a locking mechanism or the like only when in its operative condition. The lock further includes non-mechanical key identification means. The lock further includes retaining means for retaining the actuator arrangement releasably in its inoperative condition. The retaining means is linked to the key identification means and operative in response to a signal received therefrom to permit displacement of the actuator arrangement to its operative condition. The actuator arrangement typically includes an inner member, an outer member and a coupling whereby the inner and outer member are coupled together to permit relative longitudinal displacement between the inner and outer member and inhibit relative rotational movement.