Absolutely no instructions but simple to turn on. Hold the button down for about 3 seconds or until you see it light up. Has 3 settings, high-red, blue-medium, and green for low heat. Heats up super fast on the highest setting within seconds. Pads are small so surface area size of heat is low, but this entire setup appears to be constructed mainly for inserting inside of a jacket of some sort. Or maybe a blanket. The wires are (frustratingly) too long to use as is. Does take a tremendous amount of power at the highest setting if you are using a powerbank with this but it gets pretty hot. You'd have to be in a cold environment on that high setting or it will start to have a burning smell if the pads are touching other fabric. Blue setting is a good test of how hot it will get. Then you can work from there if you need more heat. Pads look and feel durable like a wood-cotton feel. Performs very well for a USB heater. Only issue is installing this. I doubt anyone looking at this product let alone people who purchased this expects do to anything beyond pluging it in for heat. I've tried many other USB heating pads and this is the only one that performs properly. You just have to be creative on how you will use this so it will work for you.