Everjia Well Heated Knee Massager for Pain Relief Heated Knee Braces for Arthritis Stress Relief Cordless Rechargeable Knee Massager with Vibration for Knee Pain Relieve Fatigue (1 Pair)

They worked right out of the box. I must have not paid enough attention because the top is not big enough for my thigh. I did the bottom strap and tried them. That worked well as I was simply sitting. The heat didn't get very warm but the vibrations felt good.