The Lenovo 5B11N56341 is an internal lithium-ion battery for a laptop, providing battery power when the computer is away from an outlet. Its three-cell design has a stated capacity of 57 Wh, for compatible systems that use this battery component.
The listed electrical specifications are 11.52 V and 4948 mAh. Compatibility is identified for Lenovo ThinkPad E14 Gen 5 and ThinkPad E16 Gen 1 variants, including models in those series. This is a laptop battery component, not an external power adapter.