You can hook 2 head units to 1 xducer with the US3 switch ...
Humminbird 720070-1 US3 Unit Switch: Amazon.ca: Sports & Outdoors
Note: only 1 head unit can use the xducer at a time with the US3 switch...
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Or you can connect the xducer to 1 head unit and use an Ethernet cable between the the 2 head units and select which sonar data is seen on each unit in the Network menu ...
Ethernet cables come in 2, 10, 15, 20, and 30ft lengths ...
Humminbird | AS EC 30E
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If you are also wanting to connect the 1199 ... You will also need the AS ETH 5PXG expansion switch ...(more than 2 Ethernet devices requires the AS ETH 5PXG) ...
Humminbird | AS ETH 5PXG
And you also will need the AS EC QDE adapter cable to connect an Ethernet cable to the 1199 (the 1199 has a different Ethernet connection) ...
Humminbird | AS EC QDE
Rickie