This cable may be used to connect optional reset switches or movement sensors back to the Aquatrip AT201, AT301 or AT401 Control Units. To enable actual connection to the Control Units accessory socket, you will require optional Part # PBC-AT cable with plug for AT201 Systems; Part # ANT2-0N or ANT2-3N for AT301 Systems. The AT401 system does not require any extra accessory for connection of a reset device.