Number of Batteries6 Lithium Ion batteries required.BrandLaptrixBattery Cell CompositionLithium IonCompatible Phone ModelsPart Numbers: HP CA06 CA06XL 718677-421 718678-421 718755-001 718756-001 HSTNN-DB4Y HSTNN-LB4X HSTNN-LB4Y HSTNN-LB4Z HSTNN-LP4ZPart Numbers: HP CA06 CA06XL 718677-421 718678-421 718755-001 718756-001 HSTNN-DB4Y HSTNN-LB4X HSTNN-LB4YBattery Type :6 Cell Lithium-Ion Voltage &Capacity : 11.1V 4400 MAH High CapacityPart Numbers: HP CA06 CA06XL 718677-421 718678-421 718755-001 718756-001 HSTNN-DB4Y HSTNN-LB4X HSTNN-LB4Y HSTNN-LB4Z HSTNN-LP4ZCompatible Models: HP ProBook 640 G0, HP ProBook 640 G1 HP ProBook 645 G0, HP ProBook 645 G1 HP ProBook 650 G0, HP ProBook 650 G1 HP ProBook 655 G0, HP ProBook 655 G1