When you're filling up at the gas station, have you ever wondered how the gas pump knows when to shut off? Hint: It's not electronic sensors.

(And you should. “Topping off” your tank is one of the potentially dangerous gas-pumping mistakes you might make.) But how does that work? How does the pump “know” the tank is full?

This home-built boost pump ... gas (like oxygen) and compress it with a hydraulic style air powered cylinder to raise the pressure. With the increased pressure, the O2 can be added to a SCUBA tank ...

California Attorney General Rob Bonta is reminding residents that if they bought gas in Southern California between February ...