The Model A was the first Ford to use the standard set of driver controls with conventional clutch and brake pedals, throttle, and gearshift. Previous Fords used controls that had become uncommon to drivers of other makes. The Model A's fuel tank was situated in the cowl, between the engine compartment's fire wall and the dash panel. It had a visual fuel gauge, and the fuel flowed to the carburetor by gravity. A rear-view mirror was optional. In cooler climates, owners could purchase an aftermarket cast iron unit to place over the exhaust manifold to provide heat to the cab. A small door provided adjustment of the amount of hot air entering the cab. The Model A was the first car to have safety glass in the windshield.