Feature: This massage device works on TENS (transcutaneous electrical nerve stimulation) which apply electrical energy to the skin causes stimulation of the dermal nervous receptors to help muscle relax. That means our device will not cause any vibration. TENS (transcutaneous electrical nerve stimulation) is kind of practical method for acute conditions,such as renal colic or acute neuralgia. Different with normal vibrated massage device, Tens massage neck can work on dermal nervous receptors to reach relaxation. Operation 1.Take out the equipment from the case,Apply 2 pieces AAA batteries. 2.Place the Massage patch pads at desired areas of the body. 3.Please push switch for power on. 4.Choice mode. 5.Adjustment for output level. 6.Working time is 12 minutes per one. 7.To push switch forOFF/DECbutton untill let lamp off. when it doesnt act during in working time. Specification Product Name: Tens electric Cervical Massager Using Mode: A-F (6 modes) Frequency: 1-100HZ Working time: 12 minutes (each round) Output: Maximun 9.8mA Weight: 55g Quantity: 1 pieces main device, 1 piece replaceable patch Color: black, blue Size: 7.5cm*15.5cm*2.5cm Notices The device can not vibrate It works by TENS. PRECAUTIONS 1.The main engine dirth point and etc on the case is cleaned by wet cloth by neutral cleaning material and wipe it by drying cloth again. 2. Do not keep it in high or low temperatures or humidity when storing the unit. 3.Dirt on the patch will affect the use effectr.