High Rate Panasonic Starved Electrolyte Cells are used in these low-profile slimline designs.The newly redesigned SLM-10 stands only 3 inches high by 1.75 inches thick yet is under 20 inches long. The SLM models all have auto-reset circuit breaker protection. All SLM units come with the ATM-PRB automatic shut-off charger. ATM version comes with Automatic Charger. XLRATM Version includes both the 4pin XLR and Automatic Charger