Abstract: The present invention 10 discloses a device for crushing stone 12 having an externally adjustable anvil ring 22. The anvil ring 22 is contained within a drum 24 and has multiple lifts 26 mounted on hydraulic support members 32 which can be adjusted from a control panel 46 either manually 48 or automatically 50. The anvils 38 are spaced about the anvil zing 22 so that the faces 52 of the multiple anvils 38 are substantially perpendicular to the line of travel of the stones 12. The anvils 38 have anchors 64 for attachment to the anvil ring 22 whereby the worn anvils 38 can be easily inverted so as to prolong anvil life.