The Castorama Transformateur 100W 110-220V France/USA is a voltage transformer designed to convert 220 volts of power to 110 volts, allowing you to use your foreign devices in countries with different electrical standards. With a power rating of 100 watts, it can handle a variety of small appliances and electronics, such as laptops, phone chargers, and hair dryers. Simply plug the transformer into a 220V outlet, connect your device to the transformer, and turn it on. The transformer features a fuse for overload protection, ensuring the safety of your devices.