Genuine 40Wh battery made by DELL, model number 91T8W, a high-performance 14.6V battery. This is a genuine DELL product purchased from the DELL STORE about two years ago as a spare battery for a VOSTRO 3559. Although it is unopened, it has been stored in its original packaging, so the "packaging vinyl" has some scratches. - Brand: DELL - Battery Capacity: 40Wh - Model Number: 91T8W - Voltage: 14.6V Compatible Notebooks Vostro 3449 3445 3549 3446 3546 3559 Latitude 3540 3440 Inspiron 3441 3721 5721 5521 3521 3421 5421 55537 3437 3437 3437 3521 43437 37 7 57 3 7 3737 3537 3442 3542 5735 5748 3541 3531 3543 5749 3443 Thank you for viewing.