An aggressive tread focused on traction and control in loose and varied terrain, with beveled leading edge dual row knobs in the center and well-spaced, siped edge knobs to dig into loose corners.
Designed to be run on 50mm rims, the 2.75" casing inflates about 27.5" overall diameter (that's pert near 650b, folks), meaning you get some benefits of a larger diameter tyre like ground approach angle and more footprint, with easier maneuverability of a smaller diameter tyre, plus some extra pneumatic cushioning.
Minimum rim size for these bad boys is 35mm.