The Czech Republic uses automated gantries with cameras to verify OBUs and vignettes.
The fines for driving without a vignette or OBU can range from 5,000 CZK up to 20,000 CZK (approx. €800) if caught in a roadside check.
Please note: Setting the wrong number of axles on your OBU is a common mistake that will result in these heavy fines. Make sure you enter the correct vehicle details.
Realated articles:
Where can I register for the MYTO CZ and get the on-board unit (OBU)?
What vehicles must use the MYTO CZ?