Mine can handle 20A...
I just need to wire it in series to do my testing.
As TypeZero mentioned, you generally have to break the circuit and put the ammeter in series in order to use it. It's a pain, unless you either have a clamp-on ammeter (which really only works with AC, not DC) or you have the ESC out of the car already so that you can disconnect one of the wires to wire in the ammeter. (Which I have, since I have a spare car)