TENS Unit Replacement Pads - Pack of 6 Extra Large Butterfly Shaped Electrode SquaresPremium Quality TENS Electrode PadsThese medical grade TENS UNIT replacement pads are reusable, comfortable and will evenly distribute the electrical currents; Premium carbon tens machine pads provide superior high conductivity, effective relief to muscle sore, tired muscles, lower and upper back and much more Universal CompatibilityStandard 2mm pin connector of electrode pads fits most TENS (Transcutaneous electrical nerve stimulation) units;