All the benefits of DEKA PREMIUM series are presented on DEKA 558MF Flooded 12V Batteries. With this battery you will have. Flush cover design enhances overall battery performance, maintenance, safety, and convenience Fortified posts, straps, & welds resist vibration damage, maximize current transfer Enhanced crystallization of Power-Perform™ plates provides more power-per-pound Short-protector separators have thicker backweb material that prevents plate-to-plate shorts Ultra-pure demineralized electrolyte precision filled to exacting levels for extended life Power-Perform™ Plates. • Full-frame positive and negative plates prevent life robbing electrical shorts from exposed wire. • Maximizes power and energy storage capacity.