Check the listing for details. Sony WF-LS900N LinkBuds S REPLACEMENT EAR BUD Black LEFT Firmware 4.1.0. Color: Black, Condition: Open box. Listed at 24.95 USD. Authentic - Refurbished - Replacement Part - NOT A COMPLETE SET - You will receive a single "LEFT SIDE" replacement item. One original silicon ear tip will be included. Thoroughly tested and guaranteed to operate as intended by the manufacturer. NO RETURNS. Please let us know which Firmware you need. ***The replacement earbud has been updated to FIRMWARE 4.1.0 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.***** ****IF YOU NEED FIRMWARE 4.0.0 LET US KNOW AND WE WILL SEND YOU THE NEWEST UPDATE JUST RELEASED**** Initialize the headset to restore factory settings. Instructions may be found here: https://www.sony.com/electronics/support/articles/00278109#Initialize Initializing video instructions can also be found on this page.Authentic - Refurbished - Replacement Part - NOT A COMPLETE SET - You will receive a single "LEFT SIDE" replacement item. One original silicon ear tip will be included. Thoroughly tested and guaranteed to operate as intended by the manufacturer. NO RETURNS. Please let us know which Firmware you need. ***The replacement earbud has been updated to FIRMWARE 4.1.0 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.***** ****IF YOU NEED FIRMWARE 4.0.0 LET US KNOW AND WE WILL SEND YOU THE NEWEST UPDATE JUST RELEASED**** Initialize the headset to restore factory settings. Instructions may be found here: https://www.sony.com/electronics/support/articles/00278109#Initialize Initializing video instructions can also be found on this page.