https://www.dealtikka.com/total-micro-notebook-battery-1-x-lithium-ion-6-cell-5600-mah-for-lenovo-thinkpad-x220-tablet-x220i-tablet/
Total Micro - Notebook battery - 1 x lithium ion 6-cell 5600 mAh - for Lenovo ThinkPad X220 Tablet; X220i Tablet