It's a NuVinci N360, which weighs in at 2450g, according to the tech specs I just found online. It's a great hub for commuter & utility use, and I even toured with it through mountains, but it's too heavy for rugged trail use.

I see the newer versions, which have a slightly wider range of gear ratios (and are sold under a different name, but still made by Fallbrook) on some e-bikes.