The Voltage Valet Outlet USB Adapter Plug set With 2 Port USB for US, Europe, Great Britain, Australia, China, Hong Kong, was designed and manufactured with the same attention to detail and construction that Voltage Valet has always been known for. These adapters are Sonic Sealed and soldered as opposed to glue and rivets used by most other brands. This type of construction ensures durability and reliability. The USB ports are 1.0 AMP and 2.1 AMP and are independent circuits, not shared. An independent USB port provides the full AMP power to the device while a shared USB port can only provide the higher power when no other devices are connected. On our device the USB ports are always at 1.0 and 2.1 AMP's