The Vant pack has dual bullets. Even with the dual bullets you need to keep a close eye on the fit of the bullets to make sure they aren't sloppy. Otherwise, that bullet connection can build enough heat to melt the plastic around plug and eventually unsolder the connection. Like I said, this class is crazy-hard on batteries. My son's Pro4 HD 4300 was by far the hardest on the packs too and he never really liked how it felt compared to his HW 4000 or the Viper 4500 that he is currently running.