AUCH 10Pcs Black Metal Inductor Coils Toroid Ferrite Cores Anti-interference Rings, 25x15x12mm Package Content : 10 x Toroid Ferrite Core Product Name : Ferrite Core Material : Mn - Zn Metal Each Overall Size : 25 x 15 x 12mm / 0.98" x 0.59" x 0.47"(Outside Dia.*Inner Dia.*T) Color : Black