This item is a Lenovo ThinkPad 6-cell laptop battery, specifically model 75+ with FRU P/N 45N1043.
Capacity: 4400mAh (48Wh)
Voltage: 10.8V
Compatible Models: Lenovo ThinkPad E430, E440, E530, E540, and B590 series
Unique Features: Lithium-ion technology with integrated safety precautions