The cutters have enough force to slice through 4/0 (aka four aught) wire. That's the thickest solid copper wire manufactured—beyond that, it's stranded. To put it in perspective, 4/0 is basically a flexible bar of metal nearly a half-inch in diamater, and it's a good bit heftier than the fattest wires leading into most homes' breaker panels. Cutting it in a cramped box is one of the most challenging routine tasks a commercial electrician encounters. For a tool this size to do the job this quickly and with this much force—just, well, watch your fingertips.
When it arrives for $429 in mid-September, the clipper will also handle aluminum, SER cables, G-Type, paired communication cable, and underground cable. That should make the workday a little easier for most electricians and data communications guys. With this tool, they can save their hand strength to twist fat connector tips up under a cramped bus bar. More here.