Absorbs RFI right at the source before resonance and harmonics effects are transferred to neighboring components. Rectangular sleeve shape with central opening extending outward to easily straddle a cable or PCB component, introducing a significant amount of magnetic coupling and impedance. Between 30% to 40% of the impedance of our fully enclosed styles, depending on configuration. When affixed with thermally conductive adhesive to flat components, such as semiconductors, heat sink thermal dissipation occurs, increasing component efficiency. Attaches to any surface with optional adhesive foam base or common electronic adhesives.