This is a Masterplug A3USB-MP 13 Amp 3x power socket adapter with two USB charging sockets. So, you can adapt one single power socket into three and also have two USB charging points..
Very simple design, three sockets one on the front of the unit and one each on either side. The two USB sockets are mounted on the front of the unit above the power socket. The USB ports output 2.1 A spread across each port. So if you plug in one device it will output 2.1A (enough to charge anything) If you connect devices to both ports at the same time the power is spread to both ports (1.05 A each).
One socket is rarely ever enough nowadays. Great for computer, printer or TV, DVD, games console etc.