Abstract: The present/invention comprises a key device (1) for insertion into a lock, the device being switchable between two modes of operation when inserted in the lock; wherein when the key device (1) is in its first mode of operation, the device prevents the lock from being activated between its engaged and disengaged positions; and when the key device (1) is in its second mode of operation, the device enables the lock to be activated between its engaged and disengaged positions; and wherein the key device is switchable between the two modes of operation by the application of a force to the key device (1) above a predetermined threshold.