I have never heard the name of the gadget. I know ;they have a clever arrongement that
when a very small amount of gas blocks a small airhole, that triggers the shut off. But they
can fail. It used to give me fits to see a woman with a carfull of small kids set the thing and
then go into the store. Though not likely, an oveflow of gas could ignite and fry her kids.
She also had left the motor running!