Built-in Automatic Voltage Regulation boosts brownouts and reduces over-voltages back to 120V levels. Provides battery-derived AC output during blackouts for maximum peace of mind. Single phone line suppression protects modem, fax and other accessories. USB port works with free unattended shutdown software. Protection Type: DSL Fax Modem Phone Power System VA: 750 VA Backup Time at Half Load: 10 minutes 225 Watts Lines: 1.