SENTINEL DUAL is the high density version of the Premium Pro range of double-conversion on-line UPS. SENTINEL DUAL is designed to power critical loads such as servers, storage systems, telephone equipment, medical systems and industrial applications. The UPS is ideal for Blade servers with an input power factor close to Unity (1). The UPS has can be used as tower UPS or within a rackmount cabinet, and takes up only 2U in height. SENTINEL DUAL has a modern design, choice of functional formats, and represents the state-of-the-art technology from the Riello UPS research & development team. The UPS can achieve an on-line operating efficiency of 92%. For critical business continuity applications requiring long runtimes, SENTINEL DUAL can be installed with battery extension packs (ER models) with their own internal battery chargers to maintain sensible recharge times. The UPS also incorporates the Riello UPS ‘power-off’ function found in other ECO Line UPS. Premium Dual is designed to save energy when no loads are connected.