Each channel is being expanded by voltage control of the input level. Beyond this there are direct outputs and a stereo input labelled "master input", with the left input normalled to the right input. If you combine the direct outputs with the stereo input and a VCA you will get another aux send!
The Mini Expander connects to the Dubmix with a flat ribbon cable.
Master input (L normalized to R)
4 direct outs
4 level CV inputs with attenuators
passive 3U Eurorack module, 6HP wide, 25mm deep.