Li-ion 11.1V 4400mAh 312-0341 312-0342 T6840 U6256 X6753 Replacement Laptop Battery for Dell Latitude X1 Li-ion. 11.1V 4400mAh 6 cell Silver One year warranty , 30 Days Money back warranty Made from the highest quality cells Features 100% Brand New Battery Replacement Certified by CE