Set of soft silicone erection ring with lead wire. These round rings are both bipolar. and can be used separately or together. The black parts are conductive. The wire has a 2.5 mm jack connector, which is suitable for our 3 different power supply units ref. # 7850, # 7880 and # 7890 Make sure you use a sufficient amount of contact gel to make the best possible contact with the skin.