With BTN 2-FDBK you can map two buttons of a hardware MIDI Controller, that support MIDI feedback (like the X Touch Mini or the older, but powerful BCR2000) inside of Voltage Modular.
BTN 2-FDBK converts the incoming MIDI Values into CV, so you can control all things, that can be controlled by CV. Unlike Voltage Modulars build in MIDI mapping functionality, the module also takes care of the MIDI channel of incoming MIDI messages, so you can make full benefit of complexer hardware MIDI controllers. Because of BTN 2-FDBKs possibility to send parameter feedback to the controller hardware the controller shows always the right values, even if you switch presets or variations.