Wireless Pro&reg; Premium Replacement Rechargeable Battery for Plantronics CS50 CS50-USB CS55 CS60 Avaya AWH-55 Replaces Plantronics 64327-01 64399-01 64399-03 65358-01 64399-01 Premium Long Lasting Lithium Polymer 240mAh 3.75v Rechargeable Battery 1 Year Unconditional Replacement Warranty Highest Quality Available Perfect Fit for your Plantronics or Avaya Wireless Headset System Compatible with Plantronics Parts: Plantronics CS50 CS50-USB CS55 CS60 Avaya AWH-55 64327-01 64399-01 64399-03 65358-01 64399-01