Size: with 5 different size with 3/ 5/ 7/ 9/ 13 mm inner diameter;Ferrite Ring Toroid core iron 40X24X16mm. | Material:Ferrite Core with Plastic Housing; Helps to Reduce EMI on AC Power Lines. | Easy to use:Clip-on Design, Easy to Install and Change. | Widely Used:Variety of Data Cables, e.g. USB Cables, Telephone Lines, Aerial Feed, Satellite Cables, Network Cables to Shield from External Electromagnetic Interference;Reduce Electro-magnetic Interference and Improve Signal Integrity. | Package includes:26 pieces ferrite cable clips with 1pieces Ferrite Ring Toroid core iron.