There is a magnet inside it and if you massage(or rub) the palm of your hand or the sole of your feet.
It is good for your blood circulations.
The sharp(or pointed) part of the massager. which is on the outside of the ball has the same efficiency as a needle acupressure.

Product Specifications
Model #: CJ-1260
Model Name: Magnetic Accu Ball
Specialty: Magnetic acupressure Ball
Power Source: N/A
Color: Gold
Unit Dimension: TBD
Unit Weight: TBD
Package: TBD
UPC: TBD