For the toughest, outdoor use that requires batteries to deliver plenty of cranking amps to power tractors and recreational vehicles across the roughest terrain. The flush cover Group U1 is calcium maintenance-free, eliminating the need to add water and the danger of harmful acid spills and lost vent caps. These flush cover batteries deliver more power-per-pound and longer storage life season after season. Special envelope separators protect all sides of the plates, preventing internal shorting and providing superior cranking capacity. These batteries have the power to perform in winter's bitter cold and summer's scorching heat and are made in the U.S.A.