Wurth WE-ExB Common Mode Power Line Choke. Wurth WE-ExB common mode chokes offer a combined noise and burst filter and are constructed from a MnZn and NiZn core material. With increasing electromagnetic immunity characteristics these common mode chokes suppress noise in a frequency range of 100kHz to 100MHz. Suitable applications for these common mode chokes include power electronics, interference suppression in motors, common mode filters, EMC filters and mains line filters.