They ensure perfect waterproofing (IP-X7) in cable passage. They allow cable passage without disassembling any terminal connectors.Shape without edges for increased durability and to prevent possible snagging of lines. Threaded holes that facilitate mounting and allow for an infinite number of disassemblies.Each piece comes with a choice of pre-punched or punchable seals for maximum ease and flexibility of use. Packaged in a practical display blister.