AUCH 20Pcs Clip-on Ferrite Ring Core Black RFI EMI Noise Suppressor Cable Clip for 5mm/7mm/9mm/13mm Diameter Cable Package included: 20 cable clips, with 5 different size 5/ 7/ 9/ 13 mm inner diameter Ferrite core with plastic cover; Helps to reduce EMI on AC power lines Color: black,Material: magnet,plastic