Caster Wheel Steel Ball W420
If you are looking for a wheel that moves freely and can run in any direction without turning, you could use this for that application. This wheel serves as a third contact point for mobile robots, as well as a standalone wheel mounted to other object's base for easy transportation.
This caster ball is a spherical metal ball that mounts in a restraining fixture. It has a height of 20mm and a mounting hole with a distance of 40mm from each other.
It is a light-duty caster wheel ball and ideal for small scale projects.
We have a larger caster wheel here