Lenmar Replacement Battery for Plantronics 63421-01 CT11 CT12 PL-63421-01 PL-CT11 PL-CT12 Replaces OEM Fits: Plantronics 63421-01, CT11, CT12, PL-63421-01, PL-CT11, PL-CT12 3.6V / 910mAh Nickel-Metal Hydride 1 Year Warranty