Synergy Digital Laptop Battery, Compatible with HP 821691-001, 854050-421, 854050-541, 854109-850 Laptop Battery (11.55V, Li-Pol, 3800mAh)Specifications:Compatible with HP Laptop(s): 1FN05AA, 821691-001, 854050-421, 854050-541, 854109-850, EliteBook 720 G4, EliteBook 828 G4 1LH23PC, EliteBook 828 G4 1LH27PC, EliteBook 828 G4 1LH28PC, HSTNN-LB7K, HSTNN-UB7D, ST03XL, EliteBook 820 G4 Z2V91EA, EliteBook 820 G4 Z2V91ET, EliteBook 820 G4 Z2V92EA, EliteBook 820 G4 Z2V94ET, EliteBook 828 G4, EliteBook 828 G4 1LH22PC, EliteBook 820 G4 Z2V73EA, EliteBook 820 G4 Z2V73ET, EliteBook 820 G4 Z2V74EA, EliteBook 820 G4 Z2V75EA, EliteBook 820 G4 Z2V78EA, EliteBook 820 G4 Z2V79EA, EliteBook 725 G4, EliteBook 725 G4 Z2V98EA, EliteBook 725 G4 Z2V99EA, EliteBook 820 G4, EliteBook 820 G4 Z2V72EA, EliteBook 820 G4 Z2V72ET