This Large Pre-Gelled Electrode is for use with the Drive Medical PainAway TENS Unit (Sold Separately). The large size is designed to provide coverage over a large area of the user's back. Package includes one electrode. Use for persistent sore or aching muscles, and/or chronic pain relief|Designed for use on back|Long lasting|Pre-gelled|Latex-Free|For use with Drive PainAway TENS Unit Only (Sold Separately)