FINEMET® FT-3K50T F Choke Cores Hitachi Metals FINEMET® FT-3K50T F Common Mode Choke Cores are designed for high-impedance applications. The choke cores are made of FT-3 50T type material and feature high saturation magnetic flux density and high permeability. The series offers low core loss, low magnetostriction, excellent high-frequency characteristics, and excellent temperature characteristics. Hitachi Metals FINEMET® FT-3K50T F Common Mode Choke Cores provide energy-saving, electromagnetic noise reduction, and size reduction.