TENS is ideal for relieving and massaging all types of chronic pain, ideal for relieving back pain, sciatica, knee and all other joint pain. 9 pre-programmed massage modes allow you to adjust pulse width and pulse rate. The digital LCD backlight feature makes the screen clear and easy to read. Built-in timer from 10 to 60 minutes, Charge units from any mains socket (adapter included as standard) or charge from your computer (USB series supplied as standard) The operation is very simple and easy to use, it comes with comprehensive instructions and an additional guide for TENS. Lightweight and strong.