With all the discounts, the device is fire. Did not like how packed, during transportation could break easily. It is powered by two Pinky batteries. At first it seemed that the main collar does not work, the electrodes are so palpably well shot)) then it was fixed... it is necessary that there was a good contact with with with The current is distributed equally if good contact in all electrodes. In case of loss of contact begin to beat the remaining two. A sore neck, an aggravation of osteochondrosis... Specially did not drink pills, tried the device, and about the miracle)!! It became easier!!