The DSC 9VADAPTER US is a 9V, 1.25A power adapter that works with the DSC NEO HS2LCDWF9ENGN keypad primarily. In addition, if you have legacy keypads like the discontinued WTK5504, or the WT5500, the DSC 9VADAPTERUS also works for those keypads. This unit can be used to constantly supply power to your keypad so you will not have to replace the batteries.