Review on LiteFuze 1000W Voltage Converter Transformer - Step Up - 110V/220V - Circuit Breaker Protection - Heavy Duty - Wattage Detection Technology - Ultra Compact & Light - 5-Year Warranty by Stephen Schmidt

It works, but it's not a particularly secure product. The output is split-phase 240V (both "live" and "neutral" - 120V to ground). With the transformer off but not disconnected a hot leg is still energized at 120 which means they are switching the output to one pole only. A push button circuit breaker is also connected in reverse on the input neutral which in theory should open on overload but of course is not an approved means as it will not trip if a short circuit between voltage and earth occurs. If your device requires a European single phase 240 (240V phase and 0V neutral), you cannot use this transformer. I'm surprised this meets US power import standards.