An ignition interlock device (IID) is a device similar to a breathalyzer that is connected to the vehicle's dashboard.
It measures the person's BAC level and allows the car to start if the person's BAC level is within the legal BAC limit (the legal BAC level limit is programmed based on the installer).
If you are required to have an ignition interlock device (IID) installed in your car before driving, you must pay for the cost of installation and maintenance of the IID.