Working Principle of The red light therapy Device: High definition LED display screen multifunctional button adjustment with four adjustable power modes (25% 50% 75% 100%) two working modes: continuous wave and pulse wave at 10Hz; Time: adjustable from 1 to 60 minutes. You can adjust the red light therapy for pain according to the effect. A compact and convenient red light therapy wand weighing only 0.53lb. Light therapy for pain suitable for your home or office. "Infra Red Light for Body: Combind with 4pcx980nm and 4pcx810nm and 16pcx660nm. 660 nm red light therapy suitable for the surface of skin，to promote blood circulation and relieve pain in surface tissues. Hand held red light therapy of 810 nm can penetrate deeper pain areas relieve muscle stiffness and soft tissue pain. 980nm can penetrate deep tissues and relieve joint pain in the neck elbows arms back knees and other areas.(980nm cant be seen when its working which is normal)" "Better for Relieving Pain: This portable red light therapy is more physical. The devices deliver red light to the body. This therapy machine for body integrates pulse modes with red and infrared light modes. It has 4 intensity levels can deeply promote cell activity and help you relieve pain and relax muscles. Its recommended to use 3-5 times a week for 4 weeks 15 minutes each time(according to your physical condition)." Multifunction therapy: Built in battery rechargeable and noiseless and you will not experience a vibration with the handheld therapy device. therapy suitable for joint pain in elbows knees shoulders hands as well as muscle pain in your back. Also suitable for your pets dogs horses cats animals as dog  for relieve pain at home. 100% After-sales Service for the Red light device: This light therapy device includes 1*Therapy for Body Pain 1* AC Adapter with Charge Cable 1* Glasses and 1* User Manual. If there is any question with the handheld light therapy during use welcome to contact us at any time we will reply you as soon as possible within 24 hours wish you happy shopping!]