PortaPow Crystal 4 Port 4.2A USB Charger with travel plugs Charges tablets, smartphones, satnavs, ebook readers etc at high speed anywhere in the world using universal USB charging sockets 4.2A (21W) of total power and the ability to output all of it from one USB socket or shared between the four. Upto four smartphones can be charged at max speed. Its still backwards compatible with devices which charge at a lower current, the PortaPow will not charge your devices any faster than they were designed for. Four individually coloured and shaped status LEDs let you know when a device has finished charging and returned to trickle charge mode. Interchangable UK, US, European and Australian shaped plugs clip securely into place for use in almost any country worldwide Most 3rd party charges only charge iPads at 10W, the Crystal includes an 'iPad Fast' socket matching the latest iPad charger spec, allowing 20% faster iPad charging.