The Fair-Rite 7878400121 is a Toroid Core designed for a wide range of applications, including inductors, transformers, and chokes. Supreme Components International is an authorised distributor of Fair-Rite components, guaranteeing you receive genuine, high-quality products. This specific core is made from Material 78, known for its excellent performance characteristics. Its dimensions are A = 12.1 mm, B = 7.5 mm, and H = 4.6 mm. Toroid cores offer superior magnetic properties compared to other core shapes, minimizing flux leakage and maximizing inductance. Choose the 7878400121 for reliable and efficient performance in your next project. Benefit from our extensive inventory and fast shipping options.