Thwan 4 This transformator have 4 input voltage options. 100V/110V/220V and 230V.My mains is 105V. With the input selector on 110V it only delivers 210V. However with the input selector on 100V, I measured a whooping 229V. Needless to say this 5000W transformator is useful to me. One small niggle is the usb charge red led, which automatically is turned on when the unit is switched on and is kind of irritating to eye.