This device is not a part of a car, rather it can be used to measure the tire pressure. Your tires need to be checked every month or more often if needed. Tires with the correct air pressure will cause less tire wear, get better gas mileage, have better shock absorption of the road, and give better handling.
The correct tire pressure is usually located on a sticker you’ll see if you open the drivers side door. Even if the tires appear full, check them because each tire sits a bit differently. Try to get as close to the PSI (pounds per square inch) for each tire as possible without going over.