The 3.8V rechargeable lithium polymer battery pack is a 125mAh battery that is the perfect replacement for the Plantronics Poly Voyager 5200 / Voyager 5200 UC - Bluetooth wireless headphone battery.
The original battery is 120mAh, and the battery pack is 125mAh. effectively increasing the battery life of the Voyager 5200 UC (Poly) - Bluetooth headset
The rechargeable lithium-polymer battery, nominal voltage 3.8V, capacity 125mAh.