RT-1KS 1KVA / 900W Form factor: Rack Mount External Battery Pack Display: LCD Interface: RJ45 /11+RS232, SNMP slot Input voltage range: 220V: 115~300Vac Input frequency: 220V:46~60Hz, Adjustable by software Output voltage range: 220V: 220±2%Vac Output frequency (AC mode): 220V: 46~54Hz Output frequency (DC mode): 220V: 50±0.2%Hz Wave form: Sine Wave Backup time(minute, full load/half load): >5' / 14' QTY & capacity of batter: 2pcs*12V9Ah Transfer time: 0 ms Overload capability: 110%~150% lasts for 30 seconds then transfer to bypass output, over 150% lasts for 300 milliseconds. Protection: 1. Auto re-starts when AC recovers 2. Silence setup 3. Automatic charging (offline charging) 4. Battery low voltage protection 5. Overload & Short circuit protection Unit dimension (mm): 441*445*88 Net weight: 12 kg