OPTI-UPS Enhanced Series ES550C USB 550 VA 330W Battery Backup + Surge Line Interactive UPS w/ AVR USB Outlets: 3 x Battery Backup + 3 x Surge Battery Run Time: Full load runtime: 2.5 Minutes (500VA) Half load runtime: 8 Minutes (300VA) Series: Enhanced Series Input Voltage Range: 110 / 120 V Input Frequency: 50/60 Hz Input Connection: NEMA 5-15P Output Voltage: 110 / 120 V Outlet Type: NEMA 5-15R