Check the listing for details. Sony WF-1000XM4 Replacement Earbud or Case - Left Right OR Case --FIRMWARE 2.0.1. Color: Black, Condition: Used. Listed at 44.95 USD. Authentic - Open box - Replacement Part - NOT A COMPLETE SET - You will receive a single replacement item of your choosing. One original foam ear tip will be included if you purchase an ear bud. 4 to 6 hours per charge. Thoroughly tested and guaranteed to operate. ***The replacement earbud has been updated to FIRMWARE 2.0.1 and will ONLY sync with an earbud that has the same FIRMWARE. PLEASE LET US KNOW IF YOU NEED ASSISTANCE BEFORE YOU PURCHASE OUR EARBUD.***** Initializing the headset to restore factory settingsIf the headset does not operate correctly even after resetting, initialize the headset.Place the headset in the charging case, leave the lid of the charging case open and wait for lights to flash repeatedly (red) in sets of 3, then hold your fingers to the touch sensors on both the left and right units for about 10 seconds. Release your fingers when the indicators (red) of the headset start flashing red at a slower pace.The indicators (green) flash 4 times ( ), and the headset is initialized. This operation resets the headset to the factory settings and deletes all pairing information. In this case, delete the pairing information for the headset from the device and then pair them again. Return Policy:Our 100% Satisfaction Guarantee promises that our products have been tested and fully work. We accept returns up to 30 days from delivery. Items just need to be in their original condition and packaging as received. We will apply a 20% restocking fee for returns if there were no issues with the item or if you changed you mind or didn't like them. If you have any issues, please give us the opportunity to resolve your concern. If the item is defective, non working, or does not match description, please contact us for an easy return.Authentic - Open box - Replacement Part - NOT A COMPLETE SET - You will receive a single replacement item of your choosing. One original foam ear tip will be included if you purchase an ear bud. 4 to 6 hours per charge. Thoroughly tested and guaranteed to operate. ***The replacement earbud has been updated to FIRMWARE 2.0.1 and will ONLY sync with an earbud that has the same FIRMWARE. PLEASE LET US KNOW IF YOU NEED ASSISTANCE BEFORE YOU PURCHASE OUR EARBUD.***** Initializing the headset to restore factory settingsIf the headset does not operate correctly even after resetting, initialize the headset.Place the headset in the charging case, leave the lid of the charging case open and wait for lights to flash repeatedly (red) in sets of 3, then hold your fingers to the touch sensors on both the left and right units for about 10 seconds. Release your fingers when the indicators (red) of the headset start flashing red at a slower pace.The indicators (green) flash 4 times ( ), and the headset is initialized. This operation resets the headset to the factory settings and deletes all pairing information. In this case, delete the pairing information for the headset from the device and then pair them again. Return Policy:Our 100% Satisfaction Guarantee promises that our products have been tested and fully work. We accept returns up to 30 days from delivery. Items just need to be in their original condition and packaging as received. We will apply a 20% restocking fee for returns if there were no issues with the item or if you changed you mind or didn't like them. If you have any issues, please give us the opportunity to resolve your concern. If the item is defective, non working, or does not match description, please contact us for an easy return.