6 Modes Power Control Electric Neck Massager Pulse Back Infrared Heating Relief Please check the instructions before buying. Note: Vibration is invisible to the naked eye, only by putting it on your neck can you feel it at work. 1.Please settle 2 pcs AAA batteries(NOT Included); 2. Switch on button .; 3. Press ""on "" button . You will check the indicator display ""red', then change mode; 4. Bring a neck massager around your neck; 5. Press the button ""High"" until you feel an electric shock. This device uses electric current to stimulate muscles to achieve the purpose of massage. There are 6 modes in total. 15 strengths. The intensity is too low to feel noticeable. When the intensity reaches a certain level. You will feel an electric shock. Recently, many buyers say they don't work. After our verification, the situation is as follows. This massager has a total of 15 Level When the massager is turned on, the intensity may be too low to feel very small. At this time, you can press "high" to increase the intensity. Q&A: What is the cause of some tingling in the neck using the electrical plug function? A: The neck tingling is the cause of dry skin, therapeutic apparatus and the neck was not fully close, discomfort of electric pulse function, it is recommended to use a wet towel to wipe the skin or use body lution first, electrical strength should be weak after a strong, gradually adapt. (electric pulse massage is used to massage the neck meridian,not the cervical vertebra.) Q: why does the neck ache in the cervical spine therapy? A: the cervical vertebra adjustment instrument USES ergonomic design, perfect fit human body does not use the neck dimension. Please wear this product correctly when using, and maintain the correctly posture. Use 10-20minutes every day to make your neck relax.