***PLEASE LET US KNOW WHAT FIRMWARE YOU NEED*** Authentic - Open box - Replacement Part - NOT A COMPLETE SET - You will receive a single Left side replacement. One foam ear tip will be included. Guaranteed to work 8 - 10 hours per charge. Thoroughly tested and guaranteed to operate as intended by the manufacturer. All replacement parts come with the latest update. ***This replacement earbud has been updated to FIRMWARE 2.1.0 and will ONLY sync with a right side that has the same FIRMWARE. If you need firmware 2.0.1 let us know and we will send you one otherwise we will send the 2.1.0. PLEASE LET US KNOW IF YOU NEED ASSISTANCE BEFORE YOU PURCHASE OUR EARBUD.***** Initializing the headset to restore factory settings If 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.