Sanford T.E.C. MarkerThis Trace Element Certified T.E.C. marker meets the requirements regarding trace elemaent content for the nuclear energy, aerospace, electronic, aeronautic and ship building industries. Each marker is identified with the batch number of the ink. Mfg: Sanford. Mfg No: 13401SAN. Sharpie T.e.c. Marker Blk/f. Markers Permanent, Office, Business Services