For use the JPL Headset when connecting to phones with RJ11 Headset sockets
JPL Cisco RJ11 Connection Lead (for most phones) 

• Fits most standard RJ11 Headsets
• Compatible with JPL corded Headsets
• Compatible with Plantronics Headsets (U10)
• Can also use to connect direct in to some CISCO Phones models, 69XX,79XX,89XX series

***Contact us with any questions regarding compatibility