Delivered quickly to the apartment for two days, did not expect. Works like the description: light massage with the change rate, heat-happy. My Knees very fragile area, meniscus and T. d., strong massage can not be done (!), do not damage, is not pop and not back! This massager is automatically adjusted exactly as safe. I have more shoulder ache, adjust to wear two pieces on shoulders, warm and protryasti them, it was much easier! Use this massager not only for knees, but also for my shoulders. My shoulder feels really better!