HP L29959-002 is a three-cell lithium-ion battery for select HP laptops. It is identified by battery model SY03XL and the designation SY03060XL-PL.
With a listed capacity of 60 Wh, it stores energy to power a laptop when it is away from mains power.
The listing does not name compatible laptop models or give dimensions or package contents. The identifying details are part number L29959-002, model SY03XL, lithium-ion chemistry and three-cell construction.