Rogue Hybrid atlas stone molds for strongman and crossfit competition. Mold sizes are 17" that makes approximately 215lb stone and 18" that makes approximately 240lb stone. You can add a weight or foam ball to the mold to make it slightly heavier or lighter, also dependent on your skill with mixing and pouring concrete. Rogue has videos online for how to make the stones using the molds.
$75 each or $125 for both.
I have made 2-3 stones from each one, which has left behind concrete residue. The 17" mold has slight cracking around the rim where the lip meets the mold. This is from a moment of rough handling trying to remove the stone from the mold and does not affect the mold or the stone. Rogue sells these for $175 and $183 new.
Finished stones in the pictures are for illustration only and not for sale.