When compared to traditional marine batteries, Optimas Blue Top batteries run longer, recharge faster and up to 3x more, and provide more than 15x the vibration resistance. Ideal for those who need a sure-starting, strong cranking, maintenance free power source for their boat or RV. These high-performance, high-powered 12V batteries are designed with SpiralCell technology for superior vibration resistance and longer life. High-purity lead-tin alloy plates are wound with Absorbent Glass Mat Separators and tightly compressed into a cell tube that wont shed or break, even in severe conditions. There is no chance of leaking acid with a totally sealed battery like this. Lower internal resistance produces more efficient power output. Batteries are encased in polypropylene and use sulfuric acid as an electrolyte. Post Type: dual SAE 5/16 Stainless Steel stud.Dual Purpose Starting...