Sony WF-1000XM4 Black Earphone Left Side (L) Only * Operation confirmed * Pairing confirmed Please purchase with confidence as the above has been confirmed. Instant purchase without comments is also possible. If you have lost one earbud or want to revive your earphones, please consider this. Battery operation has been confirmed for over 1 hour. Battery life duration 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 the product being used, there may be small scratches or dirt that cannot be removed. Please understand that this is a used item and consider purchasing. Also, although we have thoroughly checked the operation, there are rare cases where pairing may not work well due to differences in the system firmware version of your other earbud. If you are concerned, please feel free to comment beforehand and we will check if it is a compatible version for pairing. Please note that we do not accept returns due to 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 lamp (red) starts flashing. The lamp (green) will flash 4 times, and the headset will be initialized and returned to the factory settings, and all device registration (pairing) information will be deleted. After that, you can pair and use it. Search Keywords #WH-1000XM