Basically new, rebuilt but not used, externally balanced, 918400, new hub, bolts, directions $350 obo plus shipping or pickup in Flint, MI
Looks like they replace the o-rings https://www.chevyhardcore.com/news/rebuilding-atis-super-damper-is-super-economical/
I recently ordered an ATI internal balancer and it has a different part number than the external balancer. Therefore, I would think they are two completely different animals. Mine is at the machine shop with everything else being internally balanced.