Octo I/O is a bi-directional passive expander, converting Polytip connections to 3.5mm outputs, allowing users to access each individual voice from a polyphonic module. The "mult section" enables users to multiply Polytip polyphonic signals from a single source to multiple destinations. This configuration is useful for applications such as patching OCTOSTAGES envelopes to control both OCTOPASS filters and OCTOSTAGES VCAs, providing a convenient and efficient way to manage polyphonic signals.