For small boat, transom applications (boats that do not have battery compartments), these easy access external battery terminals allow trolling motor leads and charger leads to be connected without opening the box. Built-in battery meter includes two 12-volt accessory plugs, and 2 manual reset circuit breakers (15 amp for accessory plugs and 60 amp for trolling motor). Displays current "state of charge". Fits group 24- and 27-size batteries.