Please see the images provided for details on this electrode. WIRELESS TENS COMPATIBILITY - For quick pain relief, use these self-adhesive pads with the Med-Fit Painless TENS machines to target back, joint and muscle pain. LATEX-FREE LUMBAR - The TENS self-adhesive studded pads are perfect for lower back pain. These electrodes are hypoallergenic and reduce the risk of reactions in people with latex sensitivities. REUSABLE - Each electrode is reusable for 15-20 applications and manufactured using a long-lasting hydrogel. To prolong use, apply a small amount of water to the gel every 4th application. PAINLESS TENS - The wireless TENS butterfly electrode RC340 only fits the painless TENS which is supplied with a remote control. For all other models of Painless TENS 2016-2022 please order the SA340 which is available on or the Med-Fit Store.