System 106 flush-mounted housing System 106 flush-mounted housing, 1-way, only for use with door station module and System 106 Keyless In components. For use with System 106 flush-mounted installation box with existing front panel (letterbox, door side installation, etc.). Ribbon cable, 10-pin and terminating resistors are included in the scope of delivery (exception: System 106 flush-mounted housing, 1-way).