Overview: This device is fitted with a safety system preventing more than one plug from being used at the same time. The 3 plugs must therefore be used separately. In addition, you can use the USB (Universal Serial Bus) top to quickly charge your USB (Universal Serial Bus) devices. To open: When you want to use any type of the plug, just turn the grooved plastic ring until the arrow is pointing towards the target mark. To close: Turn the grooved plastic ring until the pointer has returned to its original position. You can plug this into any available power outlet & then connect your device to the universal adaptor. If the indication light shows red, it indicates that the adaptor is working.USB charger Attach the USB (Universal Serial Bus) charger to the adapter. Plug the device specific USB (Universal Serial Bus) charging cable into the USB (Universal Serial Bus) port. The USB (Universal Serial Bus) charger can be used on electrical systems around the world, with a variable input voltage range from 110-250V. Input:110-250VAC~50-60 Hz/100m A Output:5.0VDC/500m A Specification: Weight Approx:161.3g Size Approx:8.3 x 5.7 x 5.7