ProMariner ProSportHD 20 Plus Battery Charger - The ProSportHD features a lightweight, tri-surface heatsink design. This delivers significantly faster charging through optimal cooling, while delivering true rated constant current charging amps during charge mode. Fully automatic multi-stage charging enhances battery performance while extending battery life. ProMariner Digital Technology Distributed-On-Demand(TM) Technology Heavy Duty Tri-Surface Extruded Heat Sink Design Expanded LED Display with Completion Status Gauge Lightweight Design Auto-Maintain Energy Saver Mode Fully Automatic 5-Stage Digital Performance Charging Built-in Quality and Safety Easy Installation and Operation