Whether it's arthritis or aching shoulders, the Perfect Tens device alleviates pain at the push of a button. It features two small powerful channels as well as eight preset and one manual pain relief program, each with its own combination of settings to reduce pain in different ways. The compact size of the Perfect Tens allows you to take it anywhere. The included electrodes are applied to the skin and emit small electrical impulses to stimulate the nerves in the affected area. Pain relief occurs because the Perfect Tens prevents pain signals from reaching the brain. Additionally, it stimulates the body's natural endorphin production. If an electrode is not properly placed on the skin, the strength of the impulses is automatically reset to zero.