It looks cool, but that is a horrible handle. You want it to be wood or plastic so it dampens vibrations as much as it can, and smooth so one hand can slide down the handle from near the head to your other hand at the end as you swing. A couple minutes breaking up concrete with that and your hands would be numb, tingly, and probably bloody. Gloves would help, but using this will always suck.

They can’t reproduce, should be fine.

Metric measuring systems are superior in almost every use case, with the exception, I think, of how temperature feels to us. As arbitrary as Fahrenheit seems, it does seem like a more natural scale to talk about the weather or body temp. The smaller units are nice for these purposes too. 0 being very cold and 100 being very hot feels less arbitrary than -18 and 38, even if celcius is more logical and easier to use for many other things.