Powerextra 14.4V 3500mAh Replacement Battery for iRobot Roomba 400 Series Vacumm Cleaner 100% Brand New High Quality Rechargeable replacement Battery High quality, high capacity battery for longer running time.convenient to use Safeguard features against incorrect voltage, short circuit, internal overheating. Irobot roomba 4905 400 series vacuum battery-14.4v 3.5Ah Ni-MH pack Compatible with iRobot Roomba 400 Series Floor Vac models Advanced Power System (APS) Battery.