All models are equipped with safety functions such as Key Lock, which allows you to deactivate all cooktop controls to prevent accidental use. To activate it, turn on the cooktop with the ON/OFF button, hold down any display for 3 seconds, and slide the slider from 0 to 9. To unlock, repeat the same procedure but slide from 9 to 0. Attention: you have 10 seconds to complete the operation. This function is particularly useful when children are present or when the cooktop is not in use.