A computer terminal typically includes a detachable item transfer mechanism and a docking station for receiving the detachable item transfer mechanism. The item transfer mechanism typically includes a housing defining a cavity and an opening to the cavity. The item transfer mechanism also typically includes a movable cover and a locking mechanism that is configured to secure movable cover over the opening. The locking mechanism is also typically configured to disengage the movable cover in response to a user providing authentication credentials or receiving an unlock command from the computer terminal. The computer terminal is typically configured to retrieve, via the docking station, a first item from the cavity of the item transfer mechanism and dispense, via the docking station, a second item into the cavity of the item transfer mechanism.