This device uses an electric current to stimulate muscles to achieve the purpose of massage. There are 6 modes in total. 15 strengths. The intensity is not uncomfortable nor painful to feel noticeable. When the intensity reaches a certain level. You will feel a painless electric shock that sends a signal to your nerve that signals out pain and stop it from releasing pain signals while massaging and healing your muscles. High tech powerful effect Electric Neck Massager & Pulse Back 6 Modes Power Control Far Infrared Heating Pain Relief Tool TurboTech.co Guarantee: We truly believe that we offer some of the most innovative and inspirational products in the world, and we want to ensure we back it up with a risk-free ironclad 30-day guarantee. If you don't have a positive experience for ANY reason, contact us and we will make sure that ALL your concerns are addressed and you leave 100% satisfied and smiling We have 24/7 Ticket and Email Support. Don't hesitate to contact us via e-mail or our contact form if you need assistance we're here for you. 4 GREAT REASONS TO BUY FROM US AND 4 GREAT FACTS ABOUT US… 4700+ Happy Customers Free Secured Shipping (Worldwide) Perfect Gift Ideas Guaranteed Safe Checkout Shipping Policy : All orders are shipped directly from Our Fulfillment center. The time it will take to arrive depends on the production time and availability of the products. Most orders are processed within 24 hours.