❤ Important directions for use:<br>- There are no built-in batteries, it would only work when connecting to the power source<br>- When connecting it to a power source, the LED button indicator will flash red, white, blue quickly then go out. Next, you need to turn it on by long pressing the button for 2 secs until it turns flickering red, it then starts to preheat. Long press the button for 2 secs to turn it off<br>- It starts at preheating, 5 mins later it can reach a top temp and will automatically change to medium heat setting (LED white)<br>- The heat setting is manually controlled, short press the button once to change the temp you need at any time. Red indicator is the highest temp setting, white is medium and blue is the lowest<br><br>Temperature parameters for reference:<br>❤ When using the USB cable: <br>- The output is about 5V/500mA<br>- Highest (red): the temp is 132.8-140℉<br>- Medium (white): the temp is 113.9-117.5℉<br>- Lowest (blue): the temp is 101.3-104℉<br>- If you connect it to a power bank with an output current higher than 500mA, the temp can be higher than the above measurements, and you can get more heat<br><br>❤ When using the AC adapter:<br>- The fixed output is 7.9V/1.1A<br>- Highest (red): the temp is 176-194℉<br>- Medium (white): the temp is 152.6-168.8℉<br>- Lowest (blue): the temp is 116.6-122℉<br>- There may be an error of 4-7℉for the temp measurements above because of different measure instrument and measure position! The temp values above are just for reference<br><br>❤ Note:<br>For better hot therapy experience, please wear the heat pad over a close-fitting shirt, especially for sensitive skin. Skin redness is a normal phenomenon after hot therapy<br><br>❤ Doact No. 1 priority is customer satisfaction<br>❤ Please feel free to contact us if you meet any issue about size, support, and quality. We will provide refund or replacement service to you