Amazon.co.jp: PATIKIL Ferrite Toroid Core 14mm x 8mm x 7mm 30pcs Transformer Induction Coil Ring Black : Industrial & Scientific
Dahszhi Toroid Ferrite Cores Green Inductor Coils Ferrite Ring Toroid - 100pcs: Amazon.com: Industrial & Scientific
Bettomshin 5Pcs Toroid Core Ferrite Choke Iron Powder Inductor Ferrite Ring 27.2x44.5x16.5mm,Light Green and Blue : Amazon.co.uk: Business, Industry & Science
uxcell Toroid Core, Ferrite Chokes Ring Iron Powder Inductor Ferrite Rings, Yellow White 13pcs, 8.2 x 15.5 x 6.2mm: Amazon.com: Industrial & Scientific
Xiaoyztan 5 Pcs Iron Toroid Ferrite Core Powder Inductor Ferrite Rings, Green Painted, 1.2"x0.7"x0.5": Amazon.com: Industrial & Scientific
Fielect 10Pcs Toroid Core Ferrite Choke Iron Powder Inductor Ferrite Ring 24.1x39.9x14.5mm,Black: Amazon.com: Industrial & Scientific
Amazon.co.jp: PATIKIL Ferrite Toroid Core 14mm x 8mm x 7mm 30pcs Transformer Induction Coil Ring Black : Industrial & Scientific