CFR › Title 21 › Part 882 › §882.133021 CFR §882.1330Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy link(a)Identification. A depth electrode is an electrode used for temporary stimulation of, or recording electrical signals at, subsurface levels of the brain.(b)Classification. Class II (performance standards).