Use when changing the radio in a Ford vehicle that has the original passenger airbag light built into the original radio.
 

Ford lock and hazard button assembly and airbag light unit.

Below are examples of an original Ford dashboard with the lock and hazard buttons and with and without the original airbag status light units.

Aftermarket fascias for these cars have holes for the button and light units. Depending on what is fitted originally will determine what additional buttons, light units or blanking units are required.

Below are pictures to show an aftermarket fascia with the different buttons fitted.