Metallic shielding can come in many forms and provides protection against both electromagnetic (EMI) susceptibility and emissions. Susceptibility means incoming EMI that can affect Nortech products. Emissions means EMI that goes out to other devices from Nortech products. Shielding is typically comprised of braided metal strands of wire (looks like a Chinese finger trap or maypole braid). Other shielding options include backshells, formed metal sheets, or copper foil to cover gaps.