The magneto switch allows the pilot to isolate each magneto during the runup check, in order to identify a faulty or inoperative magneto. Be sure to remove the ignition key whenever the airplane is not in use, in order to avoid risk of ignition if the propeller is moved.

The master switch is divided into BAT and ALT sides. While it is acceptable to use only the BAT side of the switch (for example, while checking lights and other equipment during preflight), extended operation with the ALT side of the switch in the off position will deplete the battery, and eventually prevent restart of the alternator.

The majority of Cessna 172s feature standard aviation headset jacks like these.

Circuit breakers for various avionics equipment, each placarded with their rated amperage.

The electric fuel pump is used for engine priming, as well as in the event of failure of the engine's mechanical fuel pump.

These are the switches for various exterior lighting. Make sure to configure your aircraft's lighting as appropriate for the flight (for example, it may be courteous to turn off your strobe lights while taxiing to the runway at night, to avoid disrupting other pilots' night vision).

The pitot heat should be on whenever you'll be entering Instrument Meteorological Conditions (IMC) and the temperature is less than 40 degrees Fahrenheit.

Circuit breakers for other equipment and buses

To use the parking brake, apply the brakes, pull the parking brake handle and rotate it 90 degrees.

The avionics master switch is divided into Bus 1 and Bus 2, so that each bus can be powered individually in case of a fault.