Feature: 1. Good Effect: Equipped with a 30 degree optical glass lens, can increase irradiance of 120mW/cm² at a distance of 1 inch, improve therapeutic effect of infrared light therapy, and shorten treatment time. 2. Well Made: Outer bulb shell is made of high quality stainless steel, sturdy and durable, not easy to damage, and can be used for a long time. 3. Wide Application: Very suitable for alleviating leg joints, back, shoulders, fingers, knees, feet, neck pain. 4. Beneficial Wavelengths Combined: Concentrated energy is larger and the penetration ability is stronger, it is suitable for physiotherapy of small area and concentrated area. 5. Relieving Pain: Near infrared light can penetrate deep into skin and directly reach pain point, thereby more effectively alleviating the pain. Specification: Item Type: Portable Infrared Therapy Device Battery: 1pc Lithium Battery (Not Include Battery) Battery Model: 18650 Application Description: 1-1: Phototherapy effect through method of physics, it emits 630nm, 660nm and 850nm light wavebands (in the same waveband as He-Ne laser, deep penetration, red light penetrates human body and red light waveband The optical effect of light (after red color) increases the influence of light on mitochondrial catalase activity, enhances cell metabolism and protein synthesis, promotes local blood circulation, and controls increase in infection Material: Stainless Steel. Package List: 1 x Physiotherapy Device1 x USB Line1 x Lanyard1 x English Manual Note: 850NM is concealed to naked eye