Quick Disconnect cable required for telecom headsets to enable direct connection to most standard telephone system handsets.The BL-10+P Geni lead is perfect for offices where there is more than one type of phone system in usethe BL-10+P Geni lead comes with a compatibility switch that allows you to adjust to the correct type of handset quickly. rather than having to have two separate leads for your phones.Simple 8-position slide adjustmentno need for a user manual. Simply slide the switch until a dial tone is heard. Standard RJ11 connector connects to virtually all telephones using a standard modular plug. Standard Plantronics compatible Quick Disconnect plug to the headset.Works with any JPL or Plantronics headset equipped with Quick Disconnect. Built-in low-current microphone amplifier enables perfect operation with telephones that require extra signal gain.