Compact and lightweight to target your pain precisely Packing enough power, this TENS unit uses low frequency electrical muscle stimulation to thoroughly massage your body. By placing the pads exactly at the site of the pain, you will get fast relief without having to digest potentially harmful or addictive prescription medicine. Meanwhile, its compact size means it’s convenient to take with you when you go to the gym, go traveling, to work or shopping etc. Safe and non-invasive TENKER TENS The TENKER TENS unit is a safe, non-invasive, drug-free method of pain relief and pain management. Many people have even used it to relieve intense pain from sports injuries, knee, foot & hip injuries, arthritis and tennis elbow. How to choose the 16 modes: 1. The "M" button cycles through the 6 main modes, the silver middle button allows choices (from 2 to 4 varieties) within that mode. In total there are 16 sub modes 2.The "T" button allows you to set the timer from 10-60 minutes, and the “+” or “-“ buttons change the intensity of the massage. Every time you change modes, the strength resets to the minimum, which is useful because you don’t want to accidentally start with the strongest setting if you change mode. Notice: 1. Please turn off the device before you touch the pads. 2. Not suitable for pregnant women and hypertension patients.