I think its an indicator of the amount of battery charge - its letting you roughly know how much battery time is left. I know of some egos that do that. I've been looking to find one like yours. Does the manual say Ego-C on it? Also, as Caridwen suggested - just measure it end to end and let us know. Pvs can seem smaller in the hand than they look in pics. But we can check for you. I have a 650 mah X2, and others will have 650 mah Egos.