Function:1. The built-in red light that reaches the inner part of the knee can clean impurities in body fluids and blood, accelerate blood circulation and remove joint effusions.2. Three-degree temperature, thermal energy penetrates the skin, accelerates blood circulation, cleanses the meridians, protects the knees from moisture and cold.3. Built-in high-frequency vibration motor , all-round knee muscle vibration massage, completely release pressure.4. Built-in laser infrared sensor lamp, wavelength 615-650NM, wavelength 4-16 nanometers, irradiates the knee joint directly into the deep layer of the knee.5. LED display, clearly visible, real-time control of massage status, one-button actuation and simple operation.Specification:Item Type: Knee MassagerMaterial : ABSBuilt-in battery: 3000mAh lithium battery;Temperature: 3 Gear Temperature (40/42/45)Working temperature: 5-40Relative humidity: 80%How to use:1. Please fully charge the product before first use. Charging time is about 2-3 hours.2. Then press the switch button to adjust the temperature, vibration and phototherapy effect according to individual needs.Package List:1 x knee massager1 x USB cable1 x Manual