Sony WF-1000XM4 Black Earbud - Left Side (L) Only * Operation confirmed * Pairing confirmed Please feel assured and purchase with confidence as the above has been confirmed. Instant purchase without comments is also possible. If you've lost one earbud or want to revive your earphones, please consider this. Battery operation has been confirmed for over 1 hour. The battery's endurance time has not been confirmed. Please note that the battery is a consumable item and is not covered by warranty. Please be sure to check the product condition in the photos. We will assume that you have agreed to the condition after purchase. Due to being a used item, there may be small scratches or dirt that cannot be removed. Please understand this is a used item and consider purchasing. Also, although we have thoroughly confirmed the operation, there are rare cases where pairing may not work due to differences in the system firmware version of the earbud you have. If you are concerned, please comment beforehand, and we will check if it is a pairing-compatible version. Please feel free to comment. Please note that we do not accept returns due to pairing issues caused by version differences after the product arrives. --Regarding Pairing Method-- Initialization Method With the headset set in the charging case and the lid open, touch and hold both the L and R touch sensors for about 10 seconds. Release your fingers when the headset's lamp (red) starts flashing. The lamp (green) will flash 4 times, and the headset will be initialized and returned to factory settings, deleting all device registration (pairing) information. After that, you can pair and use it. Search Keywords #WH-1000XM