Faraday Cage effect shields electronic components from damage due to static discharge Double track zipper is welded to the bag interior for reliability. Transparent metal bags are printed with ESD warning symbol and date coded for QC traceability. Four layer construction for puncture and tear resistance. Meets EIA 625, MIL-HDBK-263, MIL-STD-1686 and EOS/ESD standards. 3M Reclosable Static Shielding Bags 18in. x 24in. Made by 3M.