Features: 1. Wide application: This product is suitable for arthritis, sports injury, middle-aged and elderly people, etc. 2. Heating mothod: The knee heating wrap provides ultra comfy hot therapy for knee arthritis, pain relief, relieve muscle soreness and cramps. 3. 3-level temperature: 3-level temperature adjustment, you can select the temperature for different degree heat. 4. Great design: Made of OK fabric, SBR. The hook and loop fastener can be adjusted in size to makes it more comfortable to wear. 5. Power supply: USB charging, general mobile power can be used. Notice: 1. Actual color may be slightly different from the image due to different monitor and light effect. Please allow minor deviation due to manual measurement. Specification: Type: Electric Heated Knee Pad Material: OK cloth, SBR Expanded size: 56*24.5cm Power supply: USB charging Heat setting temperature parameters for reference: 1. When use the USB cable to plug in an USB port of desktop computer to get source, the output is about 5V/500mA: Highest (red): the temp is 131-134.6 Fahrenheit?5-57 degC? hot, for long term use. Medium (white): the temp is 113-118.4 Fahrenheit?5-48 degC? warm, for long term use. Lowest (blue): the temp is 96.3-104 Fahrenheit?6-38 degC? lukewarm, no need to use this setting. PS: if you connect it to a mobile power with an output current higher than 500mA, the temp can be higher than the above measurements, and you can get much heat. 2. When use the AC adapter, the fixed output is 7.9V/1.1A: Highest (red): the temp is 176-194 Fahrenheit, supper hot and heats in seconds, 10 mins later you may need change to a lower heat setting. Medium (white): the temp is 167-176 Fahrenheit, very hot, 30 mins later you may need change to the lowest setting. Lowest (blue): the temp is 118.4-122 Fahrenheit, warm, for long term use and temp buffering. includes:1 x Electric Heated Knee Pad 1 x USB cable