Through the product transfer, you can use the RJ9 interface to transfer the home phone microphone to the mobile phone.Extension Cable Adapter 3.5mm Male Jack to RJ9 4P4C Female Converter Wire for Cisco TelephoneUsed for the transfer for CISCO telephone.Interface: 3.5mm TRRS male, RJ9 4P4C telephone interface female.Length: 40cm (including connector length).Package Includes:1 Piece 3.5mm Male to RJ9 Female Cable