<p>These TENS Electrode Wires are companion for Transcutaneous Electronic Nerve Stimulator (TENS), Powered Muscle Stimulator (PMS), or Electrical Muscle Stimulation (EMS) that use the industry standard <b>2.5mm plug head</b> and <b> 3.5 mm snap-on connector</b>.<br> <br> You are suggested to make a quick check of your machine to confirm if you need the <b>2.5mm plug or 3.5mm plug</b>. <br> <br> <br> <b>We stand behind everything we sell</b>.