I am happy with this device. It is well made and the lithium battery lasts a long time. I bought it to treat my plantar fasciitis, but also to treat minor knee pain. It worked wonders on my knee pain and I will keep it for that reason. However, it has not helped my plantar fasciitis as much as I would have hoped. I may not be using it properly for this condition. I mainly use it in the heel area where it hurts. I may need to use it on other areas under the foot. Plantar fasciitis is a difficult condition to get over often taking half a year or more.