This USB massage ball only for massage purpose, not for medical treatment Massage human body for shoulder, thigh, waist, nec Features: 1) Massage human body for shoulder, thigh, waist, neck, back side, feet and hands 2) OneFeatures:1) Massage human body for shoulder, thigh, waist, neck, back side, feet and hands2) One touch on/off switch 3) Vibration speed: 3,600rpm 4) USB power: 4.0 - 5.5V ( ...