1More Concenated Energy: Song peneation ability, suitable for physiotherapy in small areas and concenated areas. 2Light Weight: Small size, easy to store and carry, can be easily put in your bag, suitable for avel. 3Near Infrared Light: Can peneate deep into the skin: directly reach the pain point, so as to relieve pain more effectively. 4Shorten eatment 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. 5Wide Range Of Applications: Very helpful for leg joint pain, back, shoulder, finger, knee, foot and neck pain. Item Type: Portable Infrared Therapy DeviceBuilt In Battery: Lithium Battery 2000mAHSize: Approx. 11.8 x 2.5cm/4.6 x 0.98inApplication Description: 1-1: Light physical therapy effect through the method of physics, it emits 660nm light bands (in the same band as the He-Ne laser, deep peneation, red light peneates 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 conols the increase in infection. 1 x Red Light Physiotherapy Device1 x USB Line1 x Lanyard