The ankle monitor continually sends a radio frequency signal containing location and other information to a receiver.
If an offender moves outside of an allowed range, the police will be notified.
They are designed to be tamper-resistant and can alert authorities to removal attempts, such as cutting the band causing a circuit break.
There are two different types of ankle monitor units: radio-frequency transmitter and GPS.
People subject to a restraining order may also be subject to GPS monitoring.