Customizable Snap Ferrite Core Kit Careful SCRC Customizable Snap Ferrite Kit with 3-13mm ID Multi-Parameter Cores in Thick PP Box for Daily Devices - RoHS & REACH Compliant Product Highlights Multi-ID Combo for Various Cable Sizes - Includes five common inner diameters (3, 5, 7, 9, and 13mm) fitting everything from slim USB leads to thick power cords Multi-Parameter Cores for Comprehensive Testing - Variety of permeability and impedance options for side-by-side testing and