At this price you are buying a small line-interactive box with a sealed lead-acid battery inside, and its job is narrow. It bridges the moment supply drops and buys enough time to save open files and close the machine down in an orderly way. Most buyers here are protecting one desktop, a monitor and the fibre equipment next to it. An abrupt cut costs more than the session: writes still in flight can leave a filesystem inconsistent, a firmware update interrupted mid-flash can leave a board refusing to boot, and repeated hard restarts wear the power supply.

Two figures decide whether a model suits you, and the larger one is the less useful. Volt-amps lead the marketing; the watt rating printed alongside is the real ceiling, and entry units commonly publish pairs such as 650VA with 360W. Add up the genuine draw of everything you intend to attach, remembering that a desktop under load pulls several times what it does sitting idle at the desktop wallpaper.

Socket fitment is a local complication worth checking before you order, because some units present the older large three-pin outlets, newer ones the smaller standard now specified for fresh installations, and many imported models only IEC outlets that need kettle leads. Scheduled national outages are behind us, yet suburban feeds still fail for planned maintenance, cable faults and storm damage, without notice and without a published timetable. Evetech dispatches from Centurion, with major centres normally reached in one to three business days and regional addresses in three to five.