FCM1608 ferrite beads are a series not carried by Digikey. We do have a list of alternates available for this series. 1608 calls out the EIA size in millimeters which is the size of the chips I listed, one of these should meet the needs for your application. When selecting an option from the list be sure to choose the proper impedance and current rating based off the chip you are looking to replace.
The TechForum Cross Reference category is for parts that Digi-Key does not sell or parts that have gone obsolete. Our Engineers and Techs have reviewed the specifications for these parts and made a recommendation for a replacement. Please review the suggested part to ensure it will work for your application.