I recently bought a few new M12 fuel battery tools from Milwaukee and I thought I would share how much I like them as I am a bit of a tool junkie. The latest one I bought being their stubby 3/8" impact, and the best of all so far. Super nice and powerful considering the size. It is rated at 250 ft-lbs, and I used it to remove the wheel nuts on my AMG GT-S which are 14 mm and hand torqued to 135 ft-lbs, and the new impact removed them, which was amazing. It is so small and light. It did take a moment to get them off, so not as fast as my brutish 1/2" 755 ft-lbs Dewalt, but so much lighter. I then used it to do a full brake job on my GT-R to swap rotors with caliper removal and it is just great.
You can see how small it is in the hand.
One of the great features of the impacts is the power selector, where one is just to torque the fastener till it is barely tight, but in that setting for removal it is at full torque. The other settings, 1 to 3 are for various RPMs and thus more and more tightening torque.
I also have a 3/8" ratchet and their 1/4" impact. Models are
2554-20 for the 3/8" impact
2552-20 for the 1/4" impact
and 2457-20 for the 3/8" ratchet
I do a lots of car work on my 5 cars, so these are now getting a lot of use and they are super nice. I bought all of mine as individual tools with no batteries and then I got a charger/battery combo.