Ferrites Toroid Cores are generally used to introduce permeability, i.e. increased inductance for a given number of turns. They are made of NiZn or NiMnZn Ferrites. Toroids provide the following advantages: ? High inductance for the physical space occupied. ? No interaction or coupling with adjacent components (unlike air wound and other inductors). ? Exceptional Q values when wound correctly and optimum core and windings selected. ? Wide range of diameters and thicknesses. ? Relatively low cost ? Often simple to mount or secure mechanically.