US Patent 7556538 Connector

A retainer (30) is formed with a wire holder (43) displaceable between a holding position for holding wires (25) in such a manner as to prevent movements of the wires (25) and a standby position for permitting the movements of the wires (25). A restricting action of a restricting portion (15) prevents the wire holder (43) from being displaced to the holding position unless the retainer (30) is assembled correctly. However, the wire holder (43) can be displaced to the holding position if the retainer (30) is assembled correctly. The assembled state of the retainer (30) can be detected based on whether a displacement of the wire holder (43) to the holding position is possible.