Piper 691-419 Pitot Heat Timer

Here we have a Piper 691-232 pitot heat timer. You might be asking yourself "what is pitot heat?" It's actually quite important, since the front opening of your pitot tube can get blocked by moisture due to precipitation, clouds or dense fog. If moisture in the tube freezes, it'll stop your airspeed indicator from working or worse still, it will give you a false reading. This pitot heater prevents moisture from freezing inside the tube.