<P>No power means no computing. With todays mission-critical networks, no network manager wants to be at the mercy of equipment or building power supply failures, and 3Com has a trio of solutions to fit a range of fault-tolerance needs. The SuperStack <SUP>®</SUP> II Redundant Power System protects up to four SuperStack II system devices from internal power supply failures. Two load-sharing bulk power supplies with two fans are fed by two independent AC lines. If one power supply or fan fails, the redundant unit automatically takes over. The SuperStack II Uninterruptible Power System protects against building power outages, brownouts, power surges, and spikes. If primary power fails or falters for any reason, the Uninterruptible Power System automatically provides power for up to four SuperStack II system units with 100 volt 50/60 Hz, 120 volt 60 Hz, or 230 volt 50/60 Hz power. The SuperStack II DC Voltage Converter provides a flexible solution for companies who want to install network equipment in telco installations, or for military installations; both environments use -48V DC power with battery backup as their power source. If the primary power source fails, the converter provides DC power for up to six SuperStack II units. DC converter cables are ordered separately. </P>