Magdev ferrite cores rectangular modulus manganese zinc magdev 29 750 48 a 2500nf rectangular modulus rm type ferrite core that uses manganese zinc material that gives higher permeability and saturation levels than nickel zinc the rm design allows for efficient winding and high pcb packing densities this ferrite core is suitable for use as highly stable extremely low loss filter inductor or resonance determining inductor also suitable as a low distortion broadband transmission at low si