My son has been wanting a battery powered impact wrench (hence the
subject line). He'd prefer one with Li-ion battery pack - this is for
removing lug nuts from his cars, as well as other things.

He has a birthday coming up this weekend, and I'd like to get him one.
Anyone have any specific recommendations - besides to just get a good
pneumatic model (I've tried that route, but he wants portability, as
he does dirt-biking in the wilds of wherever)? I need a heads-up
pretty quick, so I can order it from Amazon, or whoever.

Thanks