The SHAPE Lens Gear Kit: 0.8 Pitch for Still Lenses wraps around still lenses to make them compatible with SHAPE follow focuses that have 0.8 pitch gear wheels (as opposed to rubber wheels that can be interchanged optionally for the 0.8 pitch ones). 0.8 refers to the spacing between the teeth of a gear wheel.
Still lenses, the kind that often come with a DSLR, don't have 0.8 pitch on their focusing rings like cinema lenses do. This gear kit will outfit them with such pitch. Four rings come in the set, each different-sized to match a different range of lens diameters, and thus you'll be able to use a 0.8 follow focus with most every still lens available out there. The way the gears work is as such: a ring wraps tight around a lens and on the exterior outfits the lens with 0.8 pitch. The four ring sizes are 90, 80, 70, and 60mm in diameter, with each capable of tightening by about 10mm by means of included tightening screws.