Feature: 1. More Concentrated Energy: Strong penetration ability, suitable physiotherapy in small areas and concentrated areas. 2. Light Weight: Small size, easy to store and carry, can be easily put in your bag, suitable travel. 3. Near Infrared Light: Can penetrate deep into the skin: directly the pain point, so as to relieve pain more effectively. 4. Shorten Treatment Time: Infrared light therapy pain device is equipped with a 30 degree optical glass lens, which can increase irradiance of 120mW/cm at a distance of 1 inch, thereby improving efficacy of infrared light therapy. 5. Wide Range Of Applications: Very helpful leg joint pain, back, shoulder, finger, knee, foot and neck pain. Specification: Item Type: Portable Infrared Therapy Device Built In Battery: Lithium Battery 2000mAH Size: Approx. 11.8 x 2.5cm/4.6 x 0.98in Note: 850NM is to the naked eye Application Description: 1-1: Light physical therapy effect through the method of physics, it emits 630nm, 660nm and 850nm light bands (in the same band as the He-Ne , deep penetration, red light penetrates the human body and The optical effect of the red light band (after the red color) increases the influence of light on mitochondrial catalase activity, enhances cell metabolism and protein synthesis, promotes local blood circulation, and controls the increase in . Package List: 1 x Red Light Physiotherapy Device 1 x USB Line 1 x Lanyard Note: Product will heat up during use, do not use continuously more than 5 minutes How to use: Course of treatment is generally two to three times a day, 15‑30 minutes each time. The light should be directed at the wound as much as possible. The closer the distance, the better, and it will end in one to four days.