Best replacement rechargeable battery for Plantronics wireless headset, easy to change out. If your headset shown no power or do not last long then this battery will get your headset power on and would last as long as when you first your headset new. Replacement part number batteries 65358-01, Compatible For Plantronics C052 CS50 CS55 W710 W720 CS351n CS361n CS510 CS520 Wireless Headset System