On older Mac laptops, placing a magnet near the steep sensors sleeps the Mac. However, on newer Macs, putting magnets on the sleep sensors won't sleep Mac, such as closing the lid does.
How do sleep sensors work then? I did many tests with different laptops (12", 13" 2016/2017) etc.. I know where the sensors are, but they won't sleep the Mac, not even putting a magnet on each sensor.