If it helps the numbers on it say: 090618 30219 It is also 14.4 v battery with 3000mAh I just looked and I think I was wrong about it being for the 400 series. Please check the "mAh" on the back of the battery to make sure yours is 3000.
Never mind, just checked the Roomba website. This is what it said: Rechargeable APS 3000 mAh NiMH Battery for Roomba 400 Series, Discovery Series and Original models.