features: 1) models available: r1k, r1ks, r2k, r2ks, r3k, r3ks 2) rating capacity: 1kva/700w, 2kva/1400w, 3kva/2100w 3) input voltage: 160-276v ac 4) frequency: 46~56hz (adjustable) 5) output voltage: 220v ac±3% 6) frequency: synchronize with input (normal power supply mode), 50hz±0.5% (battery power supply mode) 7) transfer time: zero break 8) indicator: indicate for overload, battery power supply and ups using situation 9) alarm sound: alarm one time per 4 seconds for battery power supply and 1s when the battery will be exhausted; the continue alarm for abnormal situation of ups 10) overload capacity: 120% the output will be changed to bypass after continue 1min 11) communication display: rs232 + intelligent slot (equipped with monitoring software for supervise & control at real time, remote turn-off, atomic memory and turn-off cue and atomic calling