The Fair-Rite 4277353509 is a high-quality 77 Material Toroid Core, designed for optimal performance in a range of electronic applications. With dimensions of A = 12.5 mm, B = 7.5 mm, and H = 5 mm, this core is suitable for creating inductors, transformers, and other magnetic components. The 77 material offers a balance of permeability and core loss, making it a versatile choice for various frequency ranges. Supreme Components International is an authorised distributor of Fair-Rite products, ensuring you receive genuine components with full traceability. Trust SCI for your ferrite core needs.