This product is either discontinued or we cannot get that from suppliers.
Poly Plantronics Spare Battery - Cs540 86180-01, 140 mAh, Usage Headset, Lithium Polymer (Li-Polymer), Output Voltage 3.7 V DC, Thickness 500 mil.
The Plantronics 86180-01 is a spare or replacement battery that is compatible with Plantronics CS540 wireless headset. This is a genuine Plantronics OEM (not after market) Replacement Battery or Spare Battery.