The EMI/RFI Shielded / Screened Backshell Adaptors vary from standard Non Shielded /Unscreened versions in their ability to offer 360° protection from Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI) in harsh environments. This is achieved by having excellent conductivity between the connector Backshell Adaptor and the terminated metallic braid surrounding the cable.