The RENPHO Electric Percussion Massager has a powerful motor, long-lasting Li-ion battery, and is made out of high quality ABS plastic. It can effectively help you relieve aches and pains in your shoulders, neck, back, joints, foot, leg, and calves. It is also useful if you need to speed up muscle recovery or simply wish to relax. Ideal to use any time of the day, whether it is throughout the day, after work, or after sports.