80 50 20 ferrite core bead 80*50*20mm magnetic ring MnZn magnetic coil inductance anti interference AL 3900 nH/N2 AG|ferrite core|ferrite ring coremagnetic core - AliExpress
Toroids
Ferrite Ring Flat Coil Color Code Inductor Insulated Wire - China Inductor and Ferrite Core Inductor
China Toroidal Mn-Zn Ferrite Core Manufacturer, Supplier and Factory - Wholesale Products - Shaanxi Fullstar Electronics Co.,Ltd