it may allow 3A current pass through.
although we can measure something like 4.9v 2A with a load resistor, most phone dun allow 2A current charging due to high wire resistance (as a result a big voltage drop).
4.9v is not enough for 2A charging for phone as the it need a higher voltage (say 5.1 v) for 2A charging, so probably u only get 1A charging.
that's why we need LG/docomo usb cable for high current charging.