Manikk Otto Active Expander is an 2HP optional expander module for use together with some other manikk modules.
The active expander gives additional features and outputs to the master module.
Read the manual for the master module carefully, to see if that module supports the Otto active expander or not. Some master modules may have support for two expanders as well.
Depth: 21 mm
+5V: 2 mA (taken from the master module)