A.S.T.M. Corrugated Switchboard, 3' W, 1/4" thick, protects against electrical shock around high voltage apparatus, meets OSHA requirements, meets all optional requirements for ozone, flame, & oil resistance, proof tested at 20,000 volts AC, Dielectric test voltage 30,000 AC RMS, tested to ASTM D-178/ANSI J6.7 TYPE II, black (priced per linear foot)