1. All-in-one world travel adaptor with dual USB charger. Dual USB ports allows for charging of USB devices. Charge your MP3 players digital cameras cell phones speakers and various other devices during your travels. 2. Covers more than 150 countries with US / EU / UK / AU plug. 3. Built-in safety shutters protect users from the direct touch of the live parts on the socket outlet. 4. Only one plug-type can be used at one time by sliding the knob selection other plug-pins are locked automatically. Note: This product may not work with certain high power appliances such as hair dryers. Check your appliance label to see if it requires less than 6A.