Warranty 1 Year Voltage 10.8V Battery Type External Cells 6 Cell Cell Type Li-ion 18650 cell Battery Capacity 4000mAh Watt-Hour 43Wh Compatible with HP 420,HP 425,HP 620,HP 625,ProBook 4320,ProBook 4320s,ProBook 4321,ProBook 4321s,ProBook 4320t,ProBook 4325s,ProBook 4326s,ProBook 4420s,ProBook 4421s,ProBook 4425s,ProBook 4520,ProBook 4520s,ProBook 4525s Compaq Compaq 320,Compaq 321,Compaq 325,Compaq 326,Compaq 420,Compaq 421,Compaq 425,Compaq 620,Compaq 621,Compaq 625