This is a 5 step "arpeggiator", being modular it's a bit more complicated than that.
It takes a CV as input, for example a triangle LFO, and converts it into a stepped CV as output. You can control the five possible CV values that it can output with the five knobs on the front panel. This way, each input gets converted to one of the five output CV’s, generating an ‘arpeggio’ when used for note CV.
The second input voltage (Root CV) gets added with all five values of the output CV. As such, it effectively ‘transposes’ your complete sequence.
https://wiki.aemodular.com/pmwiki.php/AeManual/KeuerslagerkurtFivesteps