How do i set fov for multiple cameras at once?

i am making a split screen game using Normalized Viewport Rectangle with two cameras and i want to make a slider in the options
menu for fov but i can only change the fov for the top camera using Camera.main.fieldOfView and i can’t find a way to change the other
cameras’ fov

my code:

Camera.main.fieldOfView = GUILayout.HorizontalSlider(Camera.main.fieldOfView, 30.0F, 120.0F);

hope someone can help me

Camera cameras;

void YourMethod() {
    ...

    for (int i = 0; i < cameras.Length; ++i)
    {
        cameras_.fieldOfView = GUILayout.HorizontalSlider(cameras*.fieldOfView, 30.0F, 120.0F);*_

}

}
In the editor you have to drag your two cameras to the script array cameras.