The VFI 2000 AT UPS On-Line 2000VA 1800W with 4 Schuko Sockets from Powerwalker is a Tower UPS with 4 Schuko type sockets. Its operation is (VFI) On-Line/Double Conversion which continuously provides power from its battery, protecting against voltage fluctuations and power outages. It offers pure sine wave power which is suitable for sensitive devices (e.g., medical equipment) and is preferred for devices with power supplies that have active PFC protection (e.g., computers).