The tiny cylinder on HDMI cables isn’t just for looks.

What that “mystery cylinder” actually is The black cylinder is usually a ferrite bead, sometimes called a ferrite block, ferrite core, ferrite ring, EMI filter, or ferrite choke, and it is made from a ...

Soft magnetic materials (materials that can easily be magnetized) come in many forms. For switchmode power supply flyback transformers and chokes, we would consider gapped ferrites, Iron powder, ...