The HG-1 comes built to order with either of two burr sizes, 71mm and 83mm. An interesting feature is that the burr mounts which hold the burrs in place, are inter-changeable between every HG-1. You can outfit a grinder with both sets of burrs, and use which ever one you fancy.

We’ve shot a short video illustrating how easy it is to swap the burr mount on a machine