Safe for extended use without overcharging, damaging batteries and water resistant with safety features like short circuit connection and reverse polarity protection. Fully automatic/onboard, LED status indictors and ETL listed. Complies with UL 1236,FCC Class A part 15 Specifications, 1.5 Amp, 1 bank operation, 12 volt, 6' AC input plug /wires and 6' output cable. Ring connectors for securely mounting to battery post. Designed to maintain 12-volt batteries; up to 250 amp hours. The size of the unit without the wiring is about 5" X 3.5" X 1.5".