HighlightsProfessional TENS Machine - Tens Electric Massager with 24 Modes, 20 Levels Intensity for Pain and Muscle Relief. TENS unit help relieve pain associated with sore and aching muscles in the shoulder, waist, back, neck, upper / lower extremities(arm/leg) due to strain from exercise, overwork or normal household work activities.Dual Output Design for Multi-person Use - Simultaneous dual output design allows use by two persons or for use in two different body areas. Use "+" and "-" buttons