Tenergy Dual Channel QI Wireless Charger Charging Pad for Samsung Galaxy, LG Nexus, Nokia Lumia, HTC 8X Smartphones Tenergy Dual Channel Wireless Charger have "Qi" logo and certified by WPC (Wireless Power Consortium) The charger use electromagnetic induction, and it is safe and easy to use. Charge up to 3 devices at a time (2 use Qi charging, 1 use USB cable) Compact and slim design make it ideal for traveling. Tenergy Dual Channel Qi Charger can supply maximum 20W power to mobile devices (10W for each Qi channel, and up-to 10W for USB cable ouput).