a) It consists of three parts: main unit, output cable and electrode; b) The output cable includes electric needle wire and electrode wire. The electrode includes round electrode and square electrode, and the electrode options include paste electrode, small round shaped electrodes and small conical electrodes; c) Electrodes: ① Conductive rubber electrodes: square 40mm×80mm, round Φ40mm, small round Φ20mm, small conical electrode 40mm×12mm. error are ±20%; ② Paste electrode: 40mm × 40mm, tail wire sleeve inner diameter: 2.5mm. the error is ±15%; ③ Both electrodes are the products with medical device registration certificate. Working conditions: Ambient temperature: 5℃~40℃. Relative humidity: ≤80%; Atmospheric pressure: 86KPa～106KPa. Power conditions: a) Power supply: AC 220V; b) Power frequency: 50Hz; c) Input power: 25VA. Instrument dimensions and weight: a) Overall dimensions: 300mm x 260mm x 120mm; b) Weight: about 5kg. Transcutaneous Nerve Stimulator is a low-frequency electrotherapy instrument, which acts on the human body with specific low-frequency pulsed currents through skin electrodes, or through electro-acupuncture to stimulate the A's acupuncture points, for the treatment of pain-oriented diseases. Indications: The instrument can be used for a variety of acute and chronic pain conditions: postoperative incision pain, ligament injuries, acute sprains and contusions, dysmenorrhea, joint pain, cervical spine pain, limb stump pain, upper ankylitis, sympathetic dystrophy reflexes, and so on. It can also be used for transcutaneous type therapy and highly effective electroacupuncture (electro-acupuncture).