Typical applications for high permeability ferrite toroids, 5,000µ J material, 10,000µ W material, and 15,000µ M material include common mode chokes, EMI filters, broadband transformers, pulse transformers and current transformers. Special sizes of ferrite toroids are available in 5,000 J material for Ground Fault Interrupter... Toroidal inductors and transformers are inductors and transformers which use magnetic cores with a toroidal (ring or donut) shape. They are passive electronic components, consisting of a circular ring or donut shaped magnetic core of ferromagnetic material such as laminated iron, iron powder, or ferrite, around which wire is wound. Core Material Altech Astrodyne TDI EPCOS / TDK Fair-Rite Hitachi Metals KEMET Laird Performance Materials LeaderTech Murata TDK Vacuumschmelze Wurth Elektronik Reset Jun 29, 2018 · - Toroid Core A typically popular type is made available by Micrometals and a representative example is the T50-2. This core is lacquered red (so you know the type) and has the following main properties.