An indicator is provided, which displays that it is a locking confirmable period, for predetermined time after locking the door, in a vehicle door locking and unlocking system S, which locks or unlocks the vehicle door by performing communication between a controller, which controls locking or unlocking of the vehicle door, and a portable machine. A number of resilient members are secured to the upper and on moving the foot between an extended position and a retracted position, the resilient members provide a resistive force on the foot which opposes the movement of the foot between the extended and retracted positions. The external device is configured to perform testing on the integrated circuit.