It is advantageous to use a filtered D-sub connector when electromagnetic compatibility compliance (EMC) is required or alternatively when better Electromagnetic interference (EMI) control is required. They offer an easy way to reduce EMI and RFI (radio frequency interference) from entering or exiting a device while not adding to the overall size of the connector. They can also achieve a cost-saving benefit when used instead of purchasing and installing sperate D-sub connectors and filter components.