Sony LinkBuds S Charging Case Speaker Battery 3.85V 450mAh Li-Polymer SWL800SL The Cameron Sino SWL800SL is a direct replacement for the Sony LinkBuds S Charging Case, Sony WF-LS900N Charging Case Battery. What is a Replacement Battery? Why should I choose a Cameron Sino Replacement / After Market Battery? Because Cameron Sino Batteries have better performance (higher capacity) and reliability (longevity and safety). This superior performance improves batteries running time, which is often better than the original brand replacement. This superior quality results in longer battery life and better protection of the powered device. All products are passed through a QA department which help Cameron Sino to achieve the lowest return rate in the industry.