This is a genuine Lenovo 00HW003 battery for the ThinkPad X1 Gen 3 Carbon laptop.
There are 3 generations of X1 Carbon laptops and they all use different batteries. This battery replaces the original part number "00HW002" for the 2015 version of ThinkPad X1 Carbon (3rd generation).
The 00HW002 battery is located inside the laptop and the outer laptop case will need to be removed in order to replace the battery. This is a user replaceable task if you have a small phillips head screw driver. There are 7 phillips head screws that need to be removed to pop off the keyboard cover. The keyboard will come off and expose the battery. The battery has a ribbon cable that inserts into the main circuit board. This ribbon cable will be removed and the wiring harness on your new battery will plug into the motherboard in the same opening.
This 00HW002 battery features lithium-ion cells. Li-ion battery technology provides longer run times with less weight. In addition, Li-ion batteries are not subject to the memory effect common with older battery technology. This Lenovo 00HW003 battery replacement is 100% compatible with the original battery specifications and is individually tested and backed by a 1 Year warranty.