Waterproof, Shock & Vibration Resistant, Lightweight (less than 4 pounds), compact charger designed for either portable operation or permanent mounting. Charges and maintains both flooded and sealed, maintenance free, AGM, lead acid batteries. Charges any size (capacity) lead acid battery. Float / Maintenance function maintains batteries at proper storage voltage without the damaging effects caused by trickled chargers. Reverse Polarity Protection (via external in-line fuse). Complete FOUR-Step Charging Program (Initialization, Bulk, Absorption, & Float / Maintenance). The Power Tender PLUS is easy to use, its rugged, its compact, it's packed with power, and its backed by the reputation of the undisputed battery charger industry leader, DELTRAN. 2 Year Warranty.