The SW-328 is a mechanical (non-digital) surveying wheel, 318mm outer diameter, using an analog rotation counter for basic distance rolling on paths a..
The SW-335 is a foldable digital surveying wheel, 318mm outer diameter, with a digital counter mounted on the handle, used for quick distance takeoffs..
A mechanical clickwheel-style surveying wheel with a folding handle, rotation counter, and kickstand, sized to the ~318mm wheel diameter of the SW-410..
