Tested works great. The Schumacher Pro-series Battery Charger / Engine Starter is a high-quality 50amp charger designed for automotive use. It includes clamps for easy connection and features automatic charging capabilities. Made in Germany, this unit operates at 12V and is a single item in the set. Perfect for jumpstarting engines, this charger is a reliable tool for maintaining and charging vehicle batteries. The Schumacher brand is known for its durability and efficiency in the automotive industry, making this charger a valuable addition to any workshop or garage.