specification: Item Type: Red Light Therapy Device_x000D_Material: Alloy_x000D_Built in battery: Li ion battery 2000mAh_x000D_Application description: 1-1: Phototherapy effect -----Through the method of physics, it emits light bands of 630nm (the same band as He-Ne laser, deep penetration, and red light penetrates the human body and The optical effect of the red light band (referring to the red color) increases the influence of light on the activity of mitochondrial catalase, enhances cell metabolism and protein synthesis, promotes local blood circulation, and increases infection control. Features: 1Wide Application: The physiotherapy device is very helpful for leg joint pain, back, shoulder, finger, knee, foot and neck pain. 2Portable: The physiotherapy device is lightweight and small, easy to store and carry, fits easily in your bag, and is suitable for travel use. 3Pain Relief: Near infrared light can penetrate deep into the skin and directly reach the pain point, so as to relieve pain more effectively. 4Strong Penetration: The red light therapy instrument has more concentrated energy and strong penetration, which is suitable for physiotherapy in small areas and concentrated areas. 5Optical Glass Lens: Equipped with a 30 degree optical glass lens, which can increase the irradiance of 120mW/cm at a distance of 1 inch, improve the efficacy of infrared light therapy, and shorten treatment time. PackageList: 1 x Red Light Therapy Device 1 x USBCable 1 xLanyard