CFR › Title 21 › Part 882 › §882.589021 CFR §882.5890Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy link(a)Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to electrodes on a patient's skin to treat pain.(b)Classification. Class II (performance standards).