Tens Unit is a portable, non-invasive physical therapy device. Its core feature is the use of weak, low-frequency pulsed currents, via electrodes attached to the skin, to target specific neural pathways in the body. It typically features multiple stimulation modes (such as percussion, massage, and constant), flexible adjustment of intensity, frequency, and pulse width, and a lightweight, portable, modern design. It can safely and effectively relieve acute and chronic pain (such as muscle soreness, arthritis, and low back pain), blocking the transmission of pain signals to the brain through the "gate control theory" and stimulating the body's natural production of endorphins, which have an analgesic effect. The Tens Unit is used in clinical rehabilitation, sports medicine, and daily home health care, becoming a common tool for modern people to manage pain and improve their quality of life.