AUCH 8Pcs Magnetic Clip-on Ferrite Ring Core Black RFI EMI Noise Suppressor Cable Clip for 5mm/7mm/9mm/13mm Diameter Cable Package included: 8pcs Ferrite Cable Clips(with 4 different size in, each size with 2pcs) 5MM: outer dimension--25mm x 13mm ; 7MM: outer dimension--30mm x 17mm; 9MM: outer dimension--35mm x 20mm; 13MM: outer dimension-- 36mm x 24mm Fits for cord with 5mm, 7mm, 9mm and 13mm inner diameter Color: Black Reduce electro-magnetic interference and improve signal integrity