The ProMariner 43012 is a Generation 3 ProSport 12 Charger/Maintainer by ProMariner. The ProSport 12 is an intelligent 2-bank 12 amp marine battery charger has two charging profiles for STD AGM / Flooded Batteries, and GEL Cell batteries . One of the key features of this charger is that the Pro Sport 12 is capable of sensing increased demand from the auxiliary battery and diverting up to the 100% of the available power to that battery. This incredible charger from ProMariner is also fully temperature controlled and microprocessor controlled so it will not overcharge your batteries. The ProSport 12 is an extremely durable and rugged charger that is also completely waterproof.