Typically for Wisconsin mandates you will know you need an Ignition Interlock Device (IID) or Breath Alcohol Ignition Interlock Device (BAIID) because it will be judge mandated and part of your court case. Sometimes your probation or parole officer will request you get an Ignition Interlock Device (IID) installed as well.
Disclaimer: This should not be taken as legal advice and Integrity Interlock LLC always suggests to retain legal council to help navigate your OWI/DUI court case proceedings.