2 Female To Male RJ9 4P4C Extension Cable Black Extension Cable for Telephone

Convert rj9 4p4c socket to two sockets. RJ9 Phone Training Splitter Adapter for IP Phones. rj-9 4P4C (male) rj-9 4P4C ( dual female). For outside call, both phones will ring, and you can make outside call at will; when you need to make a call, you can use either of the two phones.

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