Reef Diaper Disposable Filter Sock Replacement Elements, for Use with 4” Flange Assemblies (60 Pack)Brand: Reef Diaper Features: FILTER ELEMENTS ONLY: Requires a 4 flange assembly, sold separately or as part of the starter kit model number: S 1618 Part Number: S 1618 Details: Never wash another nasty filter sock again! Filter socks are arguably the worst part of aquarium maintenance and are the equivalent of cloth diapers that were used over 50 years ago. Why waste your time trying to clean a filter sock when you can simply replace it with a