To protect your electronics from the unwanted effects of electromagnetic interference (EMI) and radio-frequency interference (RFI), a shielded case is the way to go. These cases are typically built from high-quality aluminum and designed to attenuate radiated and conducted electromagnetic emissions. A shielded case includes a special EMI gasket secured into the lid closure. A minimum attenuation of 45 dB from 30MHz to 1GHz is typical. Cases with protection from other frequency ranges are available, too.