you can hookup 2 pigtails to the aether II.
pigtail 1 orange wire gets soldered to the orange, white/orange gets soldered to the white/orange
pigtail 2 orange wire gets soldered to the orange, white/orange gets soldered to the white/orange
once it's all hooked up, you can plug in your dmx signal to either one, then connect another dmx device to the other pigtail, it's to create a passthrough for the dmx signal.
If they didn't to it that way, you'd need a dmx splitter to run more than one aether II.