"AirPods" is a completely wireless (true wireless) earphone with separate left and right units. Even now, two years after its launch in the summer of 2016, it still boasts overwhelming sales in the earphone category. When it comes to commuting to school, you'll see many AirPods users in the same vehicle, but its popularity isn't overshadowed.
The drawback is that such AirPods are easily lost due to the structure of being completely wireless. Since it is only softly fixed near the ear canal, it may come off when you move your body or raise your arm. It's a small device, so if it comes off at the wrong time, it may be submerged, dropped into a gap, or not picked up.
In general, fully wireless earphones are "one pair with both ears". Stereo playback is realized by communicating with the smartphone on one side as the master unit and transmitting the audio signal (either the left or right channel) to the other. At that time, since each other's landmarks are used as clues to communicate with each other so as not to interfere with the nearby completely wireless earphones, in principle, only the pair at the time of purchase can be used. If you lose one, you can't do anything at the user level.
But AirPods are different. By the function of Apple's original wireless chip "W1" built-in, by resetting the left and right pair by the user's hand, it is possible to use a pair different from the one at the time of purchase. If you lose one of your AirPods, you don't have to replace both. I see AirPods one-ear listings on auction sites because AirPods have the advantage of being able to manually reset the pair (put it in the case and press and hold the settings button on the back).
Apple accepts only one exchange (lost treatment) (support page). If you bring it to a directly managed Apple Store, the charge is 7,800 yen / tax not included as of February 2019, which is cheaper than if you replaced the entire product.
