Electrotherapy Relief for Muscle & Joint PainWhat is TENS?TENS (Transcutaneous Electrical Nerve Stimulation) sends low-voltage electrical pulses through the skin to block the body's nerve pathways and stimulate endorphins (the "feel good" chemical in your brain).Dual Channel Versatility? Independent channel control for left (CH1) & right (CH2) sides? Use one side (2 Pads) or both channels (4 Pads)The iReliev Pain Relief System is a highly portable dual channel Tens device, perfect for home, work or travel. This prescription-strength system comes complete and provides best in class features, making it ideal for both acute and chronic injuries.8 Pre-set TENS ModesP1-P8 therapy programs vary in pulse width and frequency. Comfortable impulses block acute and chronic pain symptoms.25 Levels of Output IntensitySimply adjust the intensity output to reduce the perception of pain for welcome relief.