Plantronics replacement battery.

Replacement battery for the CS510, CS520, W710, W720, W410, W420, CS351, CS361, WO300,WO350 wireless headsets.

If your headset is not holding its charge for the normal time frame then it's probably due for a change.
The battery should last for approximately two years.

PLX CS510/20, W710/20, W410/20 Headset Spare Battery

SKU: 202599-03