The weighted balls inside really do all the work — I barely had to move and the rolling sensation was way more noticeable than I expected. Inserting them took a minute to figure out, but once they were in, walking around the house with them was honestly fun.
The two weighted balls give a nice rolling sensation when you move around, way more subtle than I expected. Took a little experimenting to get the angle right, but once I did it was comfortable to wear for a while.