This is a rebuild of my original Quarter Pounder. I found that the handle was a little wimpy and would break off the head. This is a stronger (extra beefy) version. The head can be filled with coins (US quarters, nickels, dimes, pennies), BB's, lead shot, nuts, washers, or whatever. I also redesigned it to be easy to print without support. I would suggest at least 3 walls, tops, and bottoms with at least 20% infill. This won't drive nails but it makes a really nice non-marring tap hammer or meat mallet. I use mint to gently whack prints off my glass bed. I'm not patient enough to wait for them to cool off. ENJOY.