Extended Performance Replacement Battery for select Asus Laptop / Notebook / Compatible with Asus X501A, X301, X301A, X301U, X401, X401A, X401U, X501, X501U, A31-X401, A32-X401, A41-X401, A42-X401 ( 6 Cell, 4400 mAh ) Battery Is Designed Using the Best Cells and Latest Safety Features to Work as a Perfect Replacment for the Original Battery. Guaranteed to Meet or Exceed Original Specifications.