UL E191581. Roxburgh EMC RES20 Series. Roxburgh EMC RES20 series single phase filters featuring excellent attenuation of conducted radio frequency interference (RFI). The RES20 series are designed for use in general purpose filtering applications where higher differential mode attenuation is required. Applications for the RES20 series include: electrical and electronic equipment; consumer goods; household equipment; building automation; machinery; electronic data/communication processing equipment; office automation. Single phase high differential attenuation For use from DC to 400Hz Compact size for rated current Fast-on, solder or wire terminations Quick and easy chassis mounting