The Fair-Rite 7898400721 is a Toroid Core designed for superior performance in a wide range of applications. Supreme Components International, an authorised distributor of Fair-Rite components, provides this core which is perfect for creating inductors, transformers, and chokes. Its toroidal shape ensures efficient magnetic flux containment, minimizing electromagnetic interference. The core is constructed from Material 78, known for its excellent permeability and low core loss characteristics. With an outer diameter of 40.64mm, an inner diameter of 24.13mm, and a height of 11.1mm, this core offers a balance of size and performance. Choose this reliable ferrite core for your next project and experience the Fair-Rite quality.