This device has been a life-saver... I suffer from chronic knee pain, which makes it difficult for me to move around. However, when I place this device on my knee, it's like magic! After using the massager for just 10 minutes, my chronic knee pain disappears, and I can do things I haven't done in a long time. I am extremely grateful for this product and can't stop recommending it to my friends who also experience knee pain. Thank you so much!